$36.00 donated in past month
From the Open-Publishing Calendar
From the Open-Publishing Newswire
Indybay FeatureRelated Categories: U.S. | Animal Liberation | Environment & Forest Defense
Spring Snails Survival Threatened by SNWA Pipeline
The spring snails of the Great Basin region are threatened by construction of the SNWA pipeline to Las Vegas. Spring snails are vital as primary consumer herbivores to reduce algae and thereby prevent eutrophication, also being the base of the trophic food web pyramid that supports trout, eagles and humans. Spring snails should be protected under ESA and are more valuable than golf courses and sprawl development north of Las Vegas.
Spring Snails Form Base of the Trophic Food Pyramid and Prevent Eutrophication in Spring Streams Threatened by the SNWA Pipeline
1) Abstract ---- pg. 1
2) Introduction ---- pg. 2
3) Spring Snail Physical Attributes ---- pg. 3
4) Spring Snail Diet and Habitat ---- pg. 4
5) Spring Snail Social Clusters and Lifestyle ---- pg. 4
6) Requirement for Listing Species as Endangered under ESA ---- pg. 5
7) Correlation between Excessive Aquifer Withdrawals and Spring Snail Population Decline ---- pg. 5
8) Carbonate Aquifer Decline Probable Given Interconnected Basin Hydraulics ---- pg. 6
9) Prior Examples of Species Extinction Following Excessive Aquifer Withdrawals ---- pg. 9
10) Reduced Spring Flow, Water Temperature and Chemistry Changes can Decrease Spring Snail Population ---- pg. 10
11) Water Permits Allocated Beyond Capacity of Yield Due to Development Pressures ---- pg. 10
12) Multifactorial Conditions Prevent Accurate Assessment of Long Term Damages and Effective Mitigation ---- pg. 11
13) Three Spring Snail Species at Risk of Extinction from SNWA Pipeline ---- pg. 12
14) Spring Snails Evolved to Overcome Ancient Climate Change, Yet Human Induced Spring Failure is Overwhelming ---- pg. 13
15) Spring Snails Form Base of Trophic Food Web Pyramid ---- pg. 13
16) Spring Snails Grazing on Periphyton and Algae Reduces Impacts of Overgrowth and Eutrophication ---- pg. 18
17) Aquifers and Spring Stream Function Best at Fullest Possible Level with Returns to Same Basin ---- pg. 28
18) Political and Financial Motivations for SNWA Pipeline Includes Development of Coyote Springs ---- pg. 43
19) A Tale of Two Texas Towns and Their Opposing Water Usage Choices ---- pg. 46
20) Long term Alternatives to SNWA Pipeline for Improving Las Vegas Water Emergency Storage Potentials ---- pg. 47
21) Conclusion ---- pg. 55
22) References ---- pg. 57
The Southern Nevada Water Authority (SNWA) claims that they need to construct a 285 mile pipeline from Snake and Spring Valley to the Las Vegas region in order for their region to continue any future development. The proposed SNWA pipeline would most likely result in lowering groundwater tables throughout the Snake, Delmar, Cave and Spring Valley aquifer system and would dry up springs. The springs emerge at specific locations and elevations where there is an opening that connects to the aquifer complex below. At the groundwater level where water is able to reach the surface permanent springs emerge to form a diverse ecosystem that exists nowhere else throughout this desert region. At the base of the spring streams’ trophic food web pyramid are algae and periphyton that are consumed by spring snails that then provide regular food sources for many predatory species such as fish, eagles and even humans. An additional role played by spring snails is prevention of eutrophication by consumption of algae and periphyton. Eutrophication results from excess nutrients such as nitrogen entering groundwater and the watershed. Even with no extra nutrients the unchecked algae and periphyton growth would choke and suffocate small spring streams without the spring snail present. Slight reductions in spring and stream flow velocity could impact spring snail communities and allow overgrowth of algae colonies and periphyton, eventually depleting streams of oxygen and causing die off of fish and other top tier consumers and predators. The protection of spring snails under the ESA is critical to maintain a healthy spring stream ecosystem. This includes preventing excessive groundwater extractions by banning any out of basin water transfers as proposed by the SNWA pipeline.
Spring snails have existed as an endemic species in the spring ecosystems of the Snake, Spring, Cave and Delmar Valley throughout the Great Basin region for thousands of years with little or no disturbances from humans, climate, predators or other natural factors. When ancient Lake Bonneville dried and shrank following prehistoric climate change the spring snails evolved over thousands of years to survive in the limited space and water conditions of the region’s remaining springs. The conditions spring snails evolved in occur in only their home spring, they are limited by requirements for specific temperatures, salinity, chemistry and other factors. This sensitivity to alterations in spring flow makes them especially vulnerable to extractions as a slight drop in groundwater levels can significantly reduce flow.
An entire ecosystem depends upon the spring snails and the algae and periphyton they feed upon. The spring fed ecosystems depend upon regular levels of groundwater as the aquifer is their only source of water. Rates of groundwater recharge need to replace the water lost to spring discharge each year, and this balance needs to continue for the springs to remain functional. The rate of recharge during the filling of this aquifer system was far greater during a wetter prehistoric climate than our currently dry desert conditions. Even local extractions need to be carefully monitored as they can also alter groundwater levels. If slight excesses from local extractions can drop groundwater levels, it follows that the proposal for regular large extractions by the SNWA would be expected to drop groundwater levels even more, resulting in reduced or eliminated spring flow. In order to protect spring snails from extinction due to loss of spring habitat from the SNWA pipeline they will need to be listed as endangered under the Endangered Species Act.
Protecting spring snails under the ESA requires understanding the source of the threat to their existence. Since they survived for thousands of years under relatively stable conditions the threat to their survival is not from any natural source. The primary threat to spring snails is a result of excessive groundwater extractions from local and external sources such as the proposed SNWA pipeline slowing down spring flows or drying them out. In this situation the human factor of developers and SNWA bureaucrats created a “perfect storm” of conditions that seriously threaten the existence of spring snails by lowering groundwater through excessive extractions.
Several developers including Mr. Harvey Whittemore and Mr. Albert Seeno have attempted to influence local politicians to support the Wingfield Company’s Coyote Springs housing development nearly 50 miles north of the Las Vegas urban core. In these satellite suburbs the property is inexpensive and developers can profit immensely from distant sites. However there is no water access for remote satellite developments and thus enter the need for the SNWA pipeline. Several other proponents of the SNWA pipeline are from other development corporations who are following the lead of Mr. Whittemore and Mr. Seeno by preparing for leapfrog development parallel to the pipeline route. The SNWA pipeline appears to directly correlate with the leapfrog development along the U.S. 93 highway corridor. This is also increasingly clear as other more reasonable options for water storage are ignored by water bureaucrats from the SNWA.
Spring Snail Physical Attributes
All spring snails are found in freshwater and have calcium carbonate shells to protect their soft invertebrate bodies. The patterned exterior of the shell is the periostracum and is made of organic matter. A shell’s completed circular turn is one whorl, and the last whorl is the spire. The first whorl, or protoconch, usually forms prior to hatching. The aperture is the shell’s opening, and some species have operculum coverings to seal the aperture (CBD, Petition pg. 16).
All 42 species of spring snail in the petition belongs to the family Hydrobiidae and 37 of these are members of the genus Pyrgulopsis. There are two anatomical regions in Hydrobiids; the head-foot region that consists of the snout, cephalic tentacles, eyes, neck and foot and the visceral coil region that is covered by the mantle. The genus Pyrgulopsis is identified by a thin and ovate-conic shell and a penis with few glands. The remaining five species on the list are members of the genus Tryonia that have elongate-conic shells. Spring snail species can be identified based upon differences in their shell and penis morphology. The male’s external penis is located behind the snout and has various lobes and glands attached, making observation of differences obvious (CBD, Petition pg. 16).
All members of family Hydrobiidae use gills to breathe and are “restricted to waters of unquestioned permanence and stability” needing springs with clean water and regular flow. All members of genus Pyrgulopsis and Tryonia are vulnerable to dehydration and any reduction in flow or alteration of the conditions of the spring could result in their demise. Hydrobiids can be found in any permanent type of spring fed ecosystem from small seeps to large gushing springs. The genus Pyrgulopsis often inhabits rheocrenes, the springs that flow out from below ground as streams and pour into a distinct channel, limnocrenes, the springs that form pools prior to entering the distinct channel and helocrenes, the springs that are shallow marshes with no open pools (CBD, Petition pg. 17).
Spring Snail Diet and Habitat
The plant communities that support spring snails with either shelter or food are water cress (Rorippa), bladderwort (Utricularia), spike rush (Eleocharis), and tule (Scirpus). Pyrgs prefer calcium carbonate rocks like travertine over soft sandy sediments while the genus Tyronia prefers both equally. Most spring snails prefer diatoms, bacteria, epiphytic algae and other aufwuchs species that attach to stones and larger plants while some include periphyton, detritus and other macrophytes in their diet (CBD, Petition pg. 19).
Hydrobiid population sizes are affected by factors are variable as water depth, stream shading, size of substrate material, water velocity at outflow, dissolved oxygen content, dissolved CO2 content, pH, salinity, water hardness, temperature, frequency of flooding and type of food. Pyrgs prefer spring temperatures between 10 to 40 degrees Celsius while Tyronia genus prefers thermal springs that are above 21 degrees, some within a narrow range. Conductivity levels for Pyrgs are between 70 – 37,000 umhos/cm. Other factors determining spring snail population size are spring brook wetted width and having armored and incised stream banks. Of the species studied so far, each one shows a strict preference to stream velocity, water temperatures and types of substrate material present in their habitat. As the spring snails have evolved with these specific conditions found in their preferred spring, these variables restrict them from other springs with different variables (CBD, Petition pg. 19).
The concentration of spring snails is greatest near the headwaters where conditions are most stable and decreases downstream as water temperature and chemistry is more variable. The need for stability in water conditions indicates that falling water levels would have drastic results for the populations of spring snails. According the USDI, any alterations in water flow, quality, temperature, clarity or mineral content can result in a direct loss of spring snails. Researchers Sada and Nachlinger concluded that spring snails need “high quality habitats with little disturbance” (CBD, Petition pg. 20).
Most spring snails are unable to relocate more than a few meters for each generation and are generally restricted to sections of their spring with conditions compatible with each species. Spring snails cannot cross dry or wet habitat that has inhospitable conditions for their species. Though some aquatic snails disperse with flood waters or hitchhiking on birds, these are mostly random mechanisms. Since spring snails have a narrow range of habitat conditions and cannot relocate, it follows that once a population has become extirpated from a spring their return is extremely improbable (CBD, Petition pg. 20).
Spring Snail Social Clusters and Lifestyle
Spring snails tend to cluster, with pyrg densities ranging from a few hundred to 10,000 per meter. Habitat sizes vary from smaller than one square meter to over 100 square meters in the larger springs. Those in warms springs reproduce continuously while cold spring residents only breed during warmer weather, both groups reproduce annually. Most pyrgs have a one year life span with many months required to attain breeding age, and then only mating once. Female pyrgs lay single egg capsules with single embryos on rock substrate that are often well secluded from predation. In just over a week the eggs hatch and babies around 0.3 mm long emerge ready to eat microscopic aquatic vegetation. As a result of low rates of reproduction combined with specific temperature and chemistry needs, the spring snails are vulnerable to extinction from variations in water levels (CBD, Petition pg. 20).
Requirement for Listing Species as Endangered under ESA
In order to protect spring snails under the Endangered Species Act (ESA) 16 U.S.C. 1533 the USFWS needs to list a species for protection if it is in danger of possible extinction in a significant section of its range. There are five factors used to determine this;
1) Present or future destruction, alteration or curtailment of habitat
2) Over harvesting for recreational, commercial, educational or scientific purposes
3) Disease or excessive predation
4) Already existing regulations ineffective
5) Other factors either human induced or natural that negatively influence their existence
If any one of the above listed factors results in a species becoming “in danger of extinction throughout all or a significant portion of its range” than the USFWS needs to classify it as endangered. If a species is “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range” then it is classified as threatened. The abstract term “foreseeable future” should include the precautionary principle and also be based upon past patterns of extinctions elsewhere when a similar action was performed (CBD, Petition pg. 21).
Correlation between Excessive Aquifer Withdrawals and Spring Snail Population Decline
Credible threats to spring snail species survival exist whenever spring flows fluctuate and lower their output velocity and amounts as a result of excessive groundwater withdrawals. Any human activity that alters water discharge, velocity, depth, temperature, substrate quality, salinity and other factors places spring snail species at risk of extinction. The spring snails that reside in the smallest springs, some less than 1 cm deep and only 1 m wide are most at risk as their springs can be easily destroyed if groundwater levels fall (CBD, Petition pg. 22).
In 2002 a study of 135 aquatic endemic taxa of the Great Basin were reviewed and it was discovered that of these 68 (approx. 50%) had lost at least one of their populations over the last 140 years. They learned that 78 of these (approx. 58%) had decreased their distribution by over one half their initial population size and 15 of the total number studied became extinct. Three of the 15 extinct species were mollusks and 12 were fish. The causes of these extinctions were multifactorial; water diversions, groundwater extractions, introduction of non-native species and pollution. Of the 135 total taxa, 67% were harmed by water flow diversions, 58% by invasive species, 40% by grazing, 13% by groundwater pumping and 2% by recreation. Synergistic effects are multifactorial and account for 60% of the taxa affected. Several other studies such as a BLM plan for the Las Vegas district found 40% of spring areas they monitored were in poor condition and none were in excellent condition. Additional tests show degradation of many springs from a combination of human factors including groundwater withdrawal, water diversions or grazing and natural ones like drought (CBD, Petition pg. 23).
Several scientists have documented the correlation between groundwater withdrawal and adverse reactions of spring fed ecosystems to altered flow patterns. They explained that in most situations the human induced groundwater withdrawals removes more water than can be replenished and the level drops can reduce spring discharge or dry them out permanently (CBD, Petition pg. 24).
The carbonate rock substrate of eastern and southern Nevada forms two different types of aquifers; shallow basin-fill of unconsolidated saturated gravels and the deeper fractured carbonate sediment rocks of dolomite and limestone. Ground flow in the shallow basin-fill gravels responds to elevation while in the deep carbonate aquifers flow is determined by hydraulic gradients influenced by recharge and discharge locations. Carbonate aquifer systems allow for regional flows that move water between basins underneath mountains that usually divide watersheds on the surface (CBD, Petition pg. 24).
The carbonate aquifer water is released at spring sites when the water table meets an opening to allow the groundwater to escape and move into a stream channel or settle into a seep. The aquifer water is the main source of spring flow and thus removing groundwater by excessive pumping will result in level drop and then a decrease or entire loss of spring flow. The loss of springs can result in extinction for these four species of Pyrgs that are endemic to this region;
Longitudinal Gland Pyrg – (Pyrgulopsis anguina)
Bifid Duct Pyrg – (Pyrgulopsis peculiaris)
Sub-globose Snake Pyrg – (Pyrgulopsis saxatilis)
Spring Valley Bifid Duct Pyrg – (Pyrgulopsis peculiaris)
These four species of spring snail are all from springs found in the Snake and Spring Valley that are targeted by the SNWA pipeline (CBD Petition pg. 25).
Carbonate Aquifer Decline Probable Given Interconnected Basin Hydraulics
According to research from 2007 by Deacon et al, the interconnected aquifers will alter the hydrology of both basins if there is groundwater withdrawal, and the approval of the SNWA pipeline would lower groundwater, reduce and eliminate many regional springs, taking with them their dependent ecosystems and local endemic species found nowhere else on Earth (CBD Petition pg. 25).
The initial hydraulic head of the spring, elevation of spring opening and the distance of the pump’s location are all factors that influence groundwater levels. Groundwater flowing through a porous medium such as carbonate rocks is proportional to the hydraulic head differential or gradient, this relationship is known as Darcy’s Law. The hydraulic head differential at springs is lowered from a drawdown cone circling around the pump. Spring discharge can be reduced as the drawdown cone extends further from the pump and lowers the hydraulic head differential (CBD Petition pg. 25).
A slight lowering of the groundwater can alter spring discharge; small low elevation springs near pumping wells and also springs at higher elevation are more sensitive to water level drops. These seemingly insignificant changes in spring discharge can wreak havoc on the aquatic ecology. If only slight changes in water level can alter the ecosystem, any large scale groundwater extraction as proposed by the SNWA pipeline would cause an ecological catastrophe. According to Zektser et al; “Groundwater overdraft develops when long-term groundwater extraction exceeds aquifer recharge, producing declining trends in aquifer storage and hydraulic head. In conjunction with overdraft, declines in surface-water levels and stream flow, reduction or elimination of vegetation, land subsidence, and seawater intrusion are well documented in many aquifers of the southwestern United States” (CBD Petition, pg. 25).
Spring snails also perform a vital service to their spring community by feasting on periphyton and algae. Without constant grazing from spring snails, algae blooms and periphyton mats would take over the spring basin and create anoxic conditions of eutrophication in which very few other animals could survive. During the Early Cambrian time the transition from stromatolite and cyanobacterial mat monoculture to greater plant and animal diversity was helped by the “small shellies“, types of snails that were the ancestors of modern spring snails. The stromatolites and cyanobacterial mats of the Early Cambrian were not eaten by anything else prior to the appearance of the ancient small shelly snails (Prothero, pg. 193).
A report by Hershler and Sada explores the relationship between biogeography and snails in the Genus Pyrgulopsis, the aquatic spring snails. The spring snails are excellent indicators of prior interconnections between basins during the Cenozoic time. Their theory is that rather than a link between the Snake River Basin of Idaho and the western Lahontan Basin, there was instead continuous drainage integration across the northern boundary of the Great Basin. The spring snails have seven different regions of endemics, five of which (Death Valley system, Lahontan Basin, Bonneville Basin, Railroad Valley and White River Basin) relate to concentrations of other endemics and two (Dixie and Steptoe) with unique snail endemism. Within each of the three largest regions of endemism (Death Valley system, Lahontan Basin, Bonneville Basin) there are two or three subregions of spring snail edemism that is not paralleled by other aquatic species (Hershler, pg. 255).
The spring snails of Genus Pyrgulopsis are gastropods from the Family Hydrobiidae and were from the late Miocene where they formed tight linkages with their aquatic habitats. Spring snails are gill breathers that require permanent waters and are unable to leave their home spring habitat due to significant terrestrial barriers. The biodiversity of spring snails is a direct result of their endemism and independent evolution with many species that are locally endemic (Hershler, pg. 255).
Throughout North America there are 131 distinct species of Pyrgulopsis of which 61% reside in the Great Basin. The authors define the Great Basin as all regions with internal drainage between the Sierra Nevada and the Rocky Mountains including the Salton Trough and the human induced diversion on the Colorado River watershed (pg. 258). The Great Basin also contains the greatest diversity of spring snails with 80 recorded species, followed by the Colorado River watershed with 20 known species. The remainder are scattered throughout the western states and Mexico from the California coast east to the Rio Grande and from as far north as the Snake and Columbia Rivers south to Mexico’s Bolson de Mapimi in Chihuahua and Coahuila (Herschler, pg. 255).
Throughout their range spring snails are plentiful in aquatic benthic communities ranging in size from small seeps to large rheocrenes and limnocrenes. Their largest numbers are found closest to the source of the spring and decline downstream (Herschler. pg. 256).
Research of ancient spring snails reveals that they were restricted to littoral zones rich in oxygen or in nearby connected springs or wetlands and were not widely dispersed in paleolakes. Currently the distribution of spring snails throughout the Great Basin is widespread and many are endemic or restricted to a single spring, spring complex or drainage basin. Of the 80 species found in the Great Basin only 16 are found across major water divide drainages (Herschler, pg. 258-9).
The largest watershed drainage within the Great Basin is the Bonneville Basin subsection that includes Thousand Springs Basin, Snake and Hamlin Valleys and the Sevier River Basin, all of which contain endemic species of spring snails only found in their home springs. These three water basins also are the western, southern and eastern boundaries with the northern boundary entering southern Idaho. The Bonneville Basin has 17 species of spring snails, 14 of which are endemic. In addition to endemic spring snails are eight species of endemic fish. The spring snails of the Bonneville Basin all differ from the species found in the nearby Lahontan Basin with only a single crossover species. The greatest concentration of endemics is found in the three regions listed above (Herschler, pg. 267).
The Thousand Springs section contains three endemics; P. hovinghi, P. lentiglans and P. millenaria. Three locally endemic species reside in the Snake Valley section; P. hamlinensis, P. anguina and P. saxatilis. Each of these three has a close relative outside of their current range; P. hamlinensis with P. montana from the Meadow Valley Wash in the Colorado River drainage over the White Rock Mt. divide to the west, P. saxatilis with P. lata from the White River Valley to the west, and P. anguina with P. chamberlini from the Sevier River Basin to the east. The connection between these three sets of different relatives shows prehistoric stream capture likely occurred. In addition the distribution of P. peculiaris from the Spring Valley to the west through the Snake Valley and into the eastern Sevier River Basin shows prior drainage interconnections between these three watersheds. Other spring snails such as P. kolobensis are distributed across the Bonneville, Lahontan and Colorado River basins with noticeable differences in appearance (Herschler, pg. 268).
The Steptoe Basin includes the Antelope, Goshute, Spring and Steptoe Valleys with eight species of which six are endemics. The only spring snail found to range in both southern and northern parts of the Steptoe Basin is the far ranging P. kolobensis. Most all of the other endemics are concentrated in the northern and southern ends of the Steptoe Basin with five located in a large spring on the basin valley floor at the east side of the Egan Range north of the town of Ely. The five species of spring snails in this single location share several attributes and could be considered a species flock. Another species overlap is witnessed in the range of P. cruciglans from the northern Steptoe Basin and also in the western side of the Bonneville Basin. This interconnection is puzzling as the prehistoric shoreline of Lake Waring was not above the sill that divided the two sections during the Pleistocene. The only endemic fish of the Steptoe Basin, Relictis solitarius is not found across the divide in the Bonneville Basin (Herschler, pg. 269).
The biogeography of the spring snails in Genus Pyrgulopsis shows that the pluvial lake drainage both conforms to the status quo of drainage theories yet also considers more complicated patterns supported by evidence of overlapping ranges, species flocks and similarities between species. This report on spring snail biogeography also shows that the prehistoric Great Basin also had interchanges with other neighboring regions (Herschler, pg. 271).
The prehistoric fossil record of spring snails in the Great Basin confirms the claims made by the Center for Biological diversity that the Genus Pyrgulopsis deserves protection as they are confined to springs within their watershed. The type of above surface interconnection between springs and watersheds no longer occurs as it did during ancient times when lakeshores were higher and easily crossed by spring snails. This is evidenced by the similarities between species in neighboring watersheds that indicate evolutionary diversions over hundreds of thousands of years when the climate was wetter and lakeshores were closer together. As this wet climate ended long ago the current conditions of minimal precipitation do not allow members of Genus Pyrgulopsis any mobility outside of their home springs and therefore leaves them vulnerable to changes such as reduced spring water velocity from excessive extractions lowering groundwater levels. In prior cases of aquifer depletion from excessive extractions other endemic species of Pyrgulopsis such as the Spring Mountains spring snail have already experienced habitat losses and extirpation.
Prior Examples of Species Extinction Following Excessive Aquifer Withdrawals
The Nevada Wildlife Action Plan from 2006 shows that several large springs have either a reduced or zero flow following groundwater pumping with resulting declines in spring ecosystems. The Las Vegas dace (Rhinichthys deaconi), a spring dependent endemic, was designated extinct in 1957 when excessive groundwater extractions dried up their regional springs. As the same time the Las Vegas springs became dried out, the nearby Pahrump Valley’s Raycraft, Bennet’s and Mase springs also dried. Soon after this the Pahrump poolfish (Empetrichthys latos), an endemic of the Pahrump Valley became extinct. The following year scientists documented the extirpation of an entire population of the Spring Mountains spring snail (Pyrgulopsis deacon) (CBD Petition, pg. 26).
Groundwater pumping decreased surface flows in Owens Valley, Devil’s Hole and Ash Meadows in the 1960s. Though pumping at Ash Meadows was reduced in the early ‘80s, ongoing withdrawals continue to lower groundwater levels and discharge from springs. In the Moapa Valley groundwater extractions resulted in 13% of the studied endemic taxa having declined from lowered surface flows (CBD Petition, pg. 26).
Excess groundwater removal has resulted in losses of connectivity between groundwater and surface water habitats in Ash Meadows and Pahrump Valley. In a 2007 report by Deacon et al. results indicate that continued groundwater removal in southern Nevada could threaten 20 species federally listed as endangered along with 137 other endemic species that depend upon spring fed ecosystems. In their report they cite that the SNWA’s proposed groundwater withdrawals alone would threaten 41 species of spring snails throughout the 78 basin region (CBD Petition pg. 26).
Reduced Spring Flow, Water Temperature and Chemistry Changes can Decrease Spring Snail Population
In addition to spring failure, the 42 petitioned species of spring snails are also vulnerable to reduced flow and water quality changes such as temperature, clarity, dissolved oxygen, conductivity, sediment transport rates, mineral content and phytoplankton growth all resulting initially from groundwater extraction. Deacon explains that reduced spring flow can cause water to cool quicker, resulting in less area of habitat available for already limited endemic species that require specific water temperature ranges to survive. He states that these springs were relatively constant for thousands of years and each spring will have specific conditions in their substrate, velocity, depth and other characteristics for a short distance downstream. Both genus Pyrgulopsis and genus Tryonia are habitat specific and have poor dispersal ability, this trait makes them vulnerable to extinction if even a single spring becomes disrupted (CBD, Petition pg. 27).
Out of the total 42 petitioned spring snails, 14 are endemic to only one location, eleven from only two sites and three are found at over ten locations. The species found at multiple sites are also vulnerable to extirpation and will probably not be able to recolonize their former habitat once that happens (CBD Petition, pg. 28).
Other risks to spring snails from groundwater withdrawal include increased erosion, sedimentation, chemical spills and hydrostatic testing discharges. A study by ENSR for Clark, Lincoln and White Pine Counties in 2007 showed groundwater withdrawal would increase short term suspended sedimentation, decreased water quality from hydrostatic testing and dust control, and change the ecosystem’s food web enough to restructure the long term community and species composition (CBD Petition, pg. 28) .
Vegetation that depends upon spring water will become extirpated from these sites also, causing additional erosion, sedimentation, altered dissolved oxygen content and increased water temps from loss of shade. Invasive species can gain entry along pipeline construction roadways and also from altered spring flows (CBD Petition, pg. 28).
Water Permits Allocated Beyond Capacity of Yield Due to Development Pressures
Human population growth in the Las Vegas region is increasing rapidly and depends upon local carbonate aquifers in addition to the supply from Lake Mead and the Colorado River. The SNWA has applications for water rights of 200,000 acre feet per year (afy) and 330,000 afy total with surrounding regions applying for 870,487 afy. If all these applications were approved and that amount of water was actually removed, scientists predict groundwater levels dropping in all 78 basins over a 130,000 square km region. Studies have indicated that the carbonate rock aquifers and local springs are interconnected and are sensitive to changes in climate and groundwater levels already overdrawn. Deacon et al. discovered in 2007 that 35 basins within the Colorado River watershed have experienced aquifer level drops with existing water rights being 102% of yearly yield. In five out of eight flow systems water rights are greater than yearly yield, and also in 65 of the total 78 basins studied for potential adverse reactions to groundwater level drops (CBD Petition, pg. 28).
Since 2006 the total permits for withdrawal were up to 735,003 afy throughout the 78 basin region, with uneven rates from 0 to 1,660 % of yield estimates for each basin. Spring snails would be threatened with extinction even if groundwater withdrawals were limited to the estimated perennial yield. According to the Nevada Division of Water Resources perennial yield’s definition does not include for maintaining wetlands, stream flows, springs and their ecosystems, groundwater level and subsurface flow between basins. Perennial yield is determined by drying of springs, death of deep rooted phreatophyte plants, groundwater levels lowering, subsidence and reduced subsurface flow between basins. When water permits are issued that are 100 percent or more of perennial yield the expected outcomes are loss of springs and land subsidence (CBD Petition, pg. 29).
Multifactorial Conditions Prevent Accurate Assessment of Long Term Damages and Effective Mitigation
Uncertainty with precipitation recharge, evapotranspiration, time needed to return to equilibrium and subsurface flows combine to prevent obtaining a definite quantification of the damages and any reliable future outcome. It is without a doubt that the state’s current distribution of water permits fails to consider the ecological balance of aquifer dependent springs and seeps. This prevents the Nevada State Engineer from correctly assessing the needs of ecological stability and biodiversity when issuing water permits that only support greater suburban sprawl of the Las Vegas region (CBD Petition, pg. 29).
Since the Nevada Division of Water Resources definition of acceptable perennial yield does not prevent the drying out of springs, the spring snails listed in the petition could become extirpated from their home springs even when groundwater extractions are not above perennial yield. If the listed spring snails depend upon the state definition of perennial yield without receiving any protection from the Endangered Species Act, the resulting drying out of springs will most probably lead to their extirpation and eventually extinction. Several groundwater studies correlate with Schaefer and Harrill’s model of groundwater levels dropping from 0.3 to 488 meters across the 78 basin area from Sevier Lake in Utah to California’s Death Valley. This prediction indicates a future balance of groundwater level drops from 15 to 152 meters over a century or two. The first century would witness declines of spring flow declines by 2-14% with continuing declines until complete spring failure. These models all agree with one another with the exception of the SNWA model that predicts an above average rate of recharge from precipitation and discharge from evapotranspiration (CBD Petition, pg. 29).
The mitigation measures proposed by the SNWA are not going to be effective at saving spring snails as most of the basins where the petitioned species live already have water rights above yearly yield. Some sites have facilities to check for adverse effects of pumping, these will not be effective at protecting spring snails from extirpation or extinction. These monitoring sites will not show subtle changes in small springs or springs at unusually high or low elevations. The springs that correctly monitor discharge flow may not have mitigation test standards matching the actual physiological needs of the spring snail, resulting in a lack of support for the species prior to spring flow being at such low levels that would require protective involvement. It is unreasonable for the FWS to claim that their stipulated agreements are enough to protect spring snail habitat as spring snails are not included in their stipulated agreement. The FWS claims to monitor ecosystem health with no clear definition of the term as it relates to an induction level that would shut off pumping immediately when negative effects on the flora and fauna are observed. The specific needs spring snails have for microhabitat factors such as water temperature and chemistry result in them being harmed by reduction of spring flow that would occur prior to monitoring level triggers (CBD Petition, pg. 29).
Three Spring Snail Species at Risk of Extinction from SNWA Pipeline
Some species most at risk in the Snake and Spring Valleys include;
Pyrgulopsis anguina or the Longitudinal Gland Pyrg that inhabits small springs and shallow rheocrenes, some only 4 meters wide with a temperature range between 16-17 degrees Celsius and containing water dependent plants such as watercress (Rorippa nasturtium-aquaticum), Baltic Rush (Juncus balticus), and muskgrass (Chara vulgaris)
Pyrgulopsis peculiaris or the Bifid Duct Pyrg that inhabits small springs and shallow rheocrenes, some with temperatures ranging between 14-18 degrees Celsius, conductivity of 317-622 micromhos/cm and containing watercress (Nasturtium officinale, Rorippa nasturtium-aquaticum), Baltic Rush (Juncus balticus), and water parsnip (Berula bess).Pyrgulopsis saxatilis or the Sub-Globose Snake Pyrg, is found only in Millard County, Utah at a single spring complex including Warm Springs, Gandy Warm Springs, and Gandy Warm Creek. Their preferred habitat there is in large rocky rheocrenes with warm temps above 26.9 degrees Celsius. All three of the above species are threatened and in danger of extirpation from several of their home springs and could be faced with extinction (CBD Petition, pg. 102).
All three of the above mentioned spring snails are at risk of further population losses from excessive groundwater withdrawal. Since Pyrgulopsis anguina and P. saxatilis only inhabit the Snake Valley, and the yearly yield there is about 25,000 afy, yet with 65,949 afy of active records for that site and with SNWA applications for 50,679 afy in Snake Valley the total aquifer level drop could be from 0.3-30 meters and render both species extinct (CBD Petition, pg. 103).
Both Pyrgulopsis peculiaris and Pyrgulopsis anguina only inhabit Big Springs and two others close by, all located in a region vulnerable to groundwater level drops from excessive drawdowns. Spring flow reductions can also have adverse effects on their habitats, leading to species extirpation as in some cases such as Warm Spring on the Utah side of Snake Valley since it is the only remaining habitat for Pyrgulopsis saxatilis. The Lincoln County Land Act is an agreement between Utah and Nevada and applies to the water usage and distribution between the states from their shared Snake Valley basin. However, the most probable outcome of this agreement will be degradation of the spring snail habitat regardless of which state secures the most water rights.
In Spring Valley the SNWA claims water rights to extract 40,000 afy initially and up to 60,000 afy in ten years, resulting in a drawdown cone that would lower and eventually eliminate surface flows of springs that P. peculiaris depends upon. If the extractions proposed by the SNWA continue at this rate, the alluvial aquifer level could fall over 200 feet in only two centuries and also lower groundwater levels in the next door basin Snake Valley. Since the yearly yield of Spring Valley is near 80,000 afy, and 84,878 afy are claimed and 166,212 afy are total active claims the groundwater level drop is estimated from between 0.3 – 3.0 meters and up to 60 meters after 75 years of extractions by the SNWA (CBD Petition, pg. 104).
This severe decline in groundwater level and spring discharge can alter the vegetation from wetland species to desert species, resulting in the extirpation of the Bifid Duct Pyrg from Turnley Spring at Sacramento Pass over two decades. Currently no groundwater withdrawal agreement between Utah and Nevada provides protection to the spring snails. The vague definitions of “ecosystem health” with no indication as to when to cease extractions would fail to protect spring snails from the adverse effects of lowered spring flow (CBD Petition, pg. 105).
Spring Snails Evolved to Overcome Ancient Climate Change, Yet Human Induced Spring Failure is Overwhelming
The biodiversity of uniquely different spring snail species shows that their home springs were flowing regularly for thousands of years and more, enabling them to evolve in relative isolation to other species from nearby spring complexes. Of the 42 spring snail species petitioned for endangered status, 38 are critically imperiled, three are imperiled and one species may already be extinct. Since spring snail habitat is restricted to only permanent springs, the presence of a healthy population of spring snails indicate that their spring was flowing regularly since prehistoric times (CBD Petition, pg. 117).
If spring snails survived in these narrow niches for thousands of years without any problems, who are modern humans to decide that now their time is up because we need more golf courses? The loss of spring snails due to anthropocentric arrogance would be a tragedy with far reaching consequences, as the entire ecosystem of fish, amphibians, reptiles and mammals is based upon the populations of spring snails as the base level of the trophic food pyramid (CBD Petition, pg. 117).
Spring Snails Form Base of Trophic Food Pyramid
According to the Nevada Wildlife Action Plan; “In addition to springs’ critical role in the survival and conservation of endemic aquatic species, they also play a very important role for other wildlife species. Nevada, which has the lowest annual rainfall in the U.S., has limited surface water resources, particularly during drought. Springs provide a vital water source between infrequent surface waters, providing water availability and food resources for a wide range of Nevada’s wildlife, from bighorn sheep, elk, and deer; to birds and bats. The broad distribution of functional spring and spring outflow systems of all types across Nevada’s landscape is an important element in maintaining Nevada’s wildlife diversity” (CBD Petition, pg. 117).
There are very few other species that can reproduce and thrive on the algae and periphyton found in springs and seeps throughout the Great Basin besides the spring snail. The level of food needed to support this base of the food pyramid depends upon a regular water source coming up from the aquifer and out of the spring. Without this water exiting the ground there would be no vegetative growth in such quality and quantity as needed to support the spring snail population. The species of frogs, reptiles, fish, birds and mammals that depend upon spring snails as their nutritious food source cannot survive without them. Removal of this crucial food source resulting from dried out springs can result in massive famine for the predatory species that rely on spring snails for a regular food source.
The trophic food pyramid or web is built upon the base level of autotrophic biomass of vegetation called primary producers that derive energy from sunlight and use photosynthesis to store this energy that is eventually ingested by the next level of heterotrophic consumers. According to the energy flow paradigm the heterotrophic consumers only convert ten percent of the energy from autotrophs into formation of heterotrophic biomass. Secondary production is not just limited to measuring the energy flowing between trophic levels as it can also explain complex interactions in ecosystems such as stoichiometry. (UA, Benke).
Secondary production can help quantify the connections between many different links on a food web or trophic pyramid diagram by measuring energy flow for each species. The energy flow webs combine data on production and diet analysis for one species or taxa expressed in mass per square meter over a specific time frame (grams m2 y-1). The energy flow shows quantitative differences between ingestion flows and linkage strengths between the species and their food source measured in total amount of food ingested be each consumer (UA, Benke).
The ratio of ingestion flows to resource production can show strength of interactions or predation pressures. A strong top-town interaction is when a predator or heterotrophic consumer ingests a large portion of the primary producer or prey or autotroph’s biomass production without considering the absolute amount of the production. The trophic position is used to describe the ranking within a trophic hierarchy in more specific detail and is calculated from the combination of ingestion flows to any species located within a flow web. The trophic position of 3.2 is more specific than a standard trophic level of three reserved for all secondary consumers (UA, Benke).
Secondary production and trophic flow webs depend upon the ability of scientists to measure production in the field, and recent research has focused on freshwater and marine benthic invertebrates. Production of specific taxon has been determined for complete invertebrate assemblages in stream ecosystems by researchers collecting assemblage wide production estimates, gut analyses and food specific ecological efficiencies. Each species can have a flow web based upon the amount of food source needed to sustain their production (UA, Benke).
A connectivity web begins the basis for determining the presence or absence of food items through gut analysis. By quantifying the gut analysis from the connectivity web a diet proportion web can be formed, which can then become an assimilation web by including measurements of ecological efficiency. Finally the assimilation web can become a quantitative flow web by using secondary production data and finally an ingestion/production web can be created to determine the trophic position of each species in the flow web (UA, Benke).
The simplest connectivity web can be built using qualitative gut content data without considering the relative proportion in the gut. Though even the most detailed connectivity webs cannot determine the varied linkage strengths between the species, they can be used to measure the number of interactions per species and the maximum food chain length from the primary producer’s base of plant resources to the highest level consumer predator. The diet proportion web based upon quantitative gut data and the percentages of different food types found can be shown as a line with relative proportions of food type consumed shown as thickness of the line with a specified percentage proportion for each food type line that adds up to 1.00 as the total food consumed. The line thickness only shows diet preferences for each consumer, not the differences in absolute ingestion. Assimilation webs or assimilation/ingestion (A/I) efficiencies show the actual absorption of the percentage of the food items used for growth and metabolism. To determine the relative amount of each food type consumed the diet proportion of food type needs to be multiplied by the assimilation efficiency. The results shown in the assimilation web are noticeably different for animals with a varied diet that have consumed food types with different assimilation efficiencies and less apparent for animals that consume from the same food type. The completed assimilation web would be combined with data on secondary production to discover the trophic basis of the amount of secondary production for a single species of consumer that is designated to a single food type. In addition the total production of all species from a single food type can be established from the assimilation web (UA, Benke).
The completed flow webs include absolute ingestion flow from a specific food type to the consumer species, obtained by dividing the production of the food type by the gross production efficiency (GPE). The GPE is the product of the A/I times the production efficiency (production divided by assimilation or P/A), written as the following equation;
GPE = (A/I) x (P/A) = P/I
Since the GPE will be a number lower than one, the total consumed food types will be much higher number than the production resulting from the consumed food. When individual ingestion flows (gm-2y-1) are recorded for each interaction a quantitative flow web can be created for the entire assemblage and community.
The quantitative food web can show the trophic level of a consumer by following the longest feeding change and can show the trophic position (TP) by adding one to the sum of the trophic position of each food type (FTP) consumed times the percentage of energy each food type gave to the consumer’s production (PE%), written as the following equation;
TP = 1 + (FTPa x PE%) + (FTBb x PE%)
In order to discover the trophic position for all species, the trophic position of the species closest to the primary production base of the trophic food web needs to be determined first (UA, Benke).
An ingestion/production (I/P) web shows the effects of predation on animals or plants from a top down perspective, measured by the consumption of the predator divided by the production of a prey species (g m-2y-1). The resulting I/P ratio is expressed without any unit measures since both values use the same unit measures, effectively canceling them out. The total sum of all the percentages of ingested food types compared to predators shows the total production percentage from consumption and the entire impacts of all predation types on a specific species. If only one predator with a P/I ratio of 0.10 does not impact prey or producer species, adding 9 additional predator species with the same P/I value would be cumulative, resulting in P/I = 0.9, with the largest total impact being 1.00 as the greatest possible impacts (UA, Benke).
The drawing of the connectivity food webs are from top to bottom with respect to feeding directions. The thickness of the lines in diet proportion food webs show percentage of food types found in the gut and in assimilation food webs show the percentage of food consumed that is used for the production of energy in the consumer. The line thickness in flow webs show the absolute flow (g m-2y-1) of each food type from below being consumed by a species and in ingestion/production (I/P) food webs show the ratio (0 – 1.00) of consumption divided by the production of prey or plant resource (UA, Benke).
The authors of the report invented a hypothetical stream ecosystem to illustrate the uses of their enhanced trophic food web. The trophic web included two primary producers (algae and detritus), a primary consumer herbivorous insect chironomid (midge), an omnivorous insect trichopteran (caddisfly), and two predaceous carnivorous insects; plecopteran (stonefly) and megalopteran (hellgrammite). The connectivity web for the hypothetical stream ecosystem shows the standard relationships between producers and consumers; with chironomids (Ch) eating algae (Al) and detritus (De) trichopterans (Tr) eating (De) and (Ch), plecopterans (Pl) eating (Ch) and (Tr), and megalopterans eating (Tr), (Pl) and (Ch). The diet proportion web based on feeding percentages shows total sum (1.00) of food consumed; for (Ch) food (Al) is 0.50 and (De) is 0.50 and for (Tr) food (De) is 0.70 and (Ch) is 0.30. The assimilation web based on efficiency of absorption of feeding percentages also shows total sum of 1.00 of food consumed and used in growth or production on consumer. For (Tr) food intake of (Ch) is 0.30, yet the high assimilation efficiency (0.70) of (Ch) results in an assimilation value of 0.75 for (Ch). Another difference is the (Ch) food intake of (Al) is 0.50, and the assimilation value of (Al) as 0.80 due to the greater absorption and digestibility of (Al) over (De) with regards to (Ch) is the primary consumer (UA, Benke).
The flow web that shows the amount of total food consumed and ecological efficiencies can often have a wide range of line thickness with values between 29 to 40,000 mg m-2y-1, this extreme variation as a result of production variation amongst the species being studied, depends mostly upon the production value of each consumer. The ingestion flow is usually greatest for the species with the highest production; with (Ch) consuming 40,000 mg m-2y-1 equally for (Al) and (De) yet having a production value of 0.80 from (Al). This discrepancy between the equal consumption rates of vegetation and the 0.80 assimilation value shows the importance of considering the assimilation efficiency of the various food types throughout the ecosystem. Other differences between production and total consumption is found when comparing the consumption percentage of 0.70 for (De) as digested food in (Tr) to 0.50 in (Ch) despite the greater total amount of (De) consumed by (Ch) in the flow web. The flow web consumption of animal prey for omnivorous (Tr) is 4,286 mg m-2y-1 yet is only 286 mg m-2y-1 for (Pl) and 1,428 mg m-2y-1 for (Me), both of which are strict carnivores (UA, Benke).
The ingestion/production (I/P) web shows the production values of prey and producers, ingestion flow per consumer, individual flow I/P and the total I/P per food source. There are also wide ranges (0.01 – 0.80) of individual impacts of consumer carnivores on producers or other primary consumer herbivores though only a narrow range (0.37 – 0.80) of total consumer influences on producer or primary consumer species. The highest influences between species are from (Ch) on (Al) at 0.80 and on (De) at 0.50, then from (Tr) on (Ch) at 0.43, next from (Me) on (Tr) at 0.36 and finally from (Me) on (Pl) at 0.57. The trophic position is obtained from the flow web data and shows five trophic levels in ascending order from producer to consumer, with (Al) and (De) at (1), (Ch) at (2), (Tr) at (3), (Pl) at (4) and (Me) at (5). The trophic position shows variation between trophic levels to express the complexity of interactions between primary and secondary consumers. Some share the same positions and levels, such as (Al) and (De) since they are both on the base level as primary producers, (Ch) is also at (2) for both position and level. Differences appear in (Tr) on level (3) and position (2.8), in (Pl) at level (4) and position (3.1) and in (Me) at level (5) and position (3.4). These differences between trophic level and trophic position indicate the need to further examine ecosystems such as spring streams to determine the sensitivity of the endemics to human changes such as lowering of the water table and reduced spring flow from excessive extractions (UA, Benke).
The flow web is the most informative trophic web as it shows actual flows instead of only ratios and can quantify the strength of the links from a bottom to top outlook. For a top to bottom outlook using the I/P web is the best option. In the instance of (Tr) consumption of (Ch) at ingestion of 0.43 shows a strong connection, though two other consumers depend upon (Ch) raising their I/P to 0.52. Certain stream ecosystems in reality show total consumption at above 90% of producer production, showing strong top to bottom impacts with diffuse predation divided between several different species of consumers (UA, Benke).
The trophic position category introduces a staggered hierarchy within the trophic level system giving additional information based upon consumption preferences, such as (Me) at trophic level (5) consuming food types at trophic positions below (3), giving (Me) a trophic position of 3.4. The trophic position concept is similar to the stable isotope (SI) methodology where there is always fractionation between trophic levels. When used in combination the bottom to top links of food webs, top to bottom links of ingestion/production webs and trophic position assessments with ratios can help provide ecosystem researchers with an improved view of the complex interactions of stream and other ecosystems (UA, Benke).
The trophic food web pyramid in unique ecosystems like springs and seeps is a precariously balanced ecosystem supported by the base producer species such as algae or detritus (dead plants or animals) and primary consumer herbivore (snails, insects, other invertebrates) that can reproduce quickly enough to feed several species of secondary consumer omni-/carnivores without suffering any significant population losses themselves. The trophic food web pyramid is generally in the shape of a triangle containing ascending trophic levels with the primary producer vegetation at the base level, next level are primary consumer herbivores and then finally secondary consumer omni-/carnivores at the very top levels.
The upper levels (4-5) of the trophic pyramid for springs and seeps of the Great Basin would include secondary or tertiary consumers such as hawks, eagles, owls, snakes, large fish including Lahontan cutthroat trout and even human residents. Below them on levels (3-4) are primary or secondary consumers such as lizards, small insectivore birds like wrens, rodents, frogs and smaller fish. The lower and broader base levels (2-3) consists primary consumers such as spring snails, insects, turtles and microscopic organisms such as zooplankton. Finally the broadest land bottom base level (1) consists of primary producers such as algae, periphyton, vascular macrophyte plants, willow trees and other streamside species of vegetation that use photosynthesis to harness energy from the sun into biomass that supports all the consumer species above them.
The population numbers of the secondary and tertiary consumers in the upper trophic levels are small in number when compared to the primary consumers in the lower trophic levels. Though the eagle on level (5) will not consume the spring snails on level (2) directly in most cases, a frog from level (3) may eat 10-20 spring snails on a given day, only to be eaten along with 3-4 other small frogs by a large snake from level (4) until finally an eagle from level (5) swoops down to eat 1-2 large snakes. The reason for the tapering effect of populations and biomass in the ascending food pyramid is energy loss. The original production energy biomass coming from vegetation on base level (1) is lost at each ascending level of the trophic pyramid due to conversion of food items to carbohydrates and proteins and indigestibility of certain food parts such as seeds, husks, shells, skins, bones, etc... Supporting a healthy population of top level (5) tertiary consumers like eagles requires a stable base of level (1) primary producer vegetation like vascular plants, algae and periphyton to support level (2) primary consumers like spring snails.
The maintenance of the trophic food web’s pyramid base of vegetation requires a steady flow of spring water and stable groundwater levels. The ecosystem services provided by spring snails include feeding frogs, snakes fish and eagles among other consumers and the constant grazing of algae and periphyton. Excessive growth of certain species of algae and periphyton can clog and choke springs and their streams by depleting the water of oxygen and causing eutrophication. Thus the spring snails of the Great Basin springs, seeps and streams perform a service in both directions of the trophic food pyramid by regulating vegetation growth and providing enough food to collectively support an extensive food pyramid on their shelly backs. If the SNWA pipeline were to be constructed and their proposed amount of water were extracted, it is probable that the reduction of flow would reduce spring snail populations and result in excessive growth of algae and eventually eutrophication of the stream surrounding the spring.
Spring Snails Grazing on Periphyton and Algae Reduces Impacts of Overgrowth and Eutrophication
Spring Snails Grazing on Periphyton and Algae Reduces Impacts of Overgrowth and Eutrophication
Though there is less run off of nitrates into the Nevada watersheds than elsewhere, their lower flows and drier climate makes them vulnerable to eutrophication from algae and periphyton mats. Eutrophication is the condition of poor water quality and reduced oxygen availability from excessive vegetation growth and the eventual die off of large amounts of vegetation being consumed by bacteria that use up a great deal of available oxygen in the process of respiration. Certain species of algae considered to be nuisance can adapt to this low oxygen and high nitrate environment and eventually replace the original species found under non-eutrophic (oligotrophic) conditions. Eutrophication from nitrates and reduced spring flow from excessive groundwater removal are linked and have been extensively researched in other regions such as Florida’s limestone springs and their streams.
In similar spring ecosystems such as those emerging from limestone aquifers in Florida that have growth of algae and periphyton eutrophication is a constant problem. The excessive level of nitrates from fertilizer runoff promotes fast growth of algae and periphyton that competes with native vascular plants and causes eutrophication. The consequences of eutrophication include bioaccumulation of toxicity, also altered habitats and trophic food webs. Over 90% of the waterways within the U.S. suffer from the effects of eutrophication from excess nutrients such as nitrogen and phosphorus. As was determined by the University of Florida researchers, snails and other invertebrates play a vital role in reducing the algae growth that leads to eutrophication (UF, Jacoby).
The springs of Florida are similar to Nevada’s springs as they are shallow and dependent on algae, vascular plants and periphyton instead of phytoplankton as their primary producers. The authors of the study intended for their research of nutrients on freshwater ecosystems to apply beyond Florida. They cite concerns of excess nutrients and eutrophication that lead to damaged ecosystems from algae blooms and loss of downstream fisheries. In Florida the nutrients enter into the aquifer through downwards percolation through the permeable karst soil. The springs are releasing nitrates and phosphorus into the surface waters (UF, Jacoby).
Nitrates are nitrogen compounds that are assimilated by algae, periphyton and other plants. Though some nitrates are natural in groundwater, excessive nitrates cause algae blooms that lead to eutrophication of downstream waters. The long term effects of eutrophication on freshwater streams are structural and functional changes to plant and algae populations. Similar to Nevada’s springs, chemistry, temperature and discharge rates are constants in Florida’s springs, making them stable-state ecosystems. There are over 700 springs in Florida that show considerable variation in these characteristics between springs and thus a diverse array of spring dependent plants and animals. The authors classify spring ecosystems as heterogeneous environments where interactions between different components such as chemistry, biology and hydrology result in specific ecosystem structures and functions (UF, Jacoby).
The complex ecosystems found around and downstream of springs are difficult to generalize based upon simple reaction to nitrates. Phosphorus and other chemicals such as dissolved oxygen, carbon dioxide and salinity can alter the type of vegetation growing there. In addition the light levels, depth of water, velocity and substrate are other factors effecting algal growth. One of the few processes limiting algae growth is grazing by invertebrates such as spring snails. If eutrophication alters the types of plants growing along streams from springs this would affect animals that depend upon them for food or shelter (UF, Jacoby).
The availability of light is altered by suspended sediments and dissolved organic matter, including algae cells. An excess of algae on the surface decreases the light needed by other macrophyte plants growing along the bottom or below the surface. The rate of discharge influenced the concentration of suspended organic matter; 5 meters cubed s-1 or more are first magnitude springs with the lowest concentration of 13 +/- 1.6 uM C L-1 and springs with lower rates of discharge showed higher values. Studies show that the streamside vegetation shading determined the level of primary producers and other macrophytes present. Shading of macrophyte plants from algae covering the leaves can reduce photosynthesis and eventually kill off the larger plants. Lower concentrations of oxygen are a limiting factor for many producers and consumers that breathe underwater. Other variables such as stream velocity, dissolved inorganic carbon (DIC), algae population and macrophyte plants are all factors that interact to influence the availability of light (UF, Jacoby).
In underwater vascular plants the greatest rate of photosynthetic carbon fixation is above the needs of leaves and tissues for carbon for respiration during saturated light levels provided that DIC is available. Most springs in Florida have high DIC levels from microbes remineralizing organic matter. There is also CO2 escaping from springs into the air at the discharge point. The DIC level only limits production when the interaction between stream velocity and algal mats lower DIC levels. Dissolved oxygen levels are important for determining the types of fauna that can survive there. Vascular plant roots also need enough dissolved oxygen in the water for aerobic breathing. The dissolved oxygen content decreases when macrophyte vascular plant leaves are covered with algae, reducing their capability for photosynthesis (UF, Jacoby).
Stream velocity and substrate are two other variables that influence types and amounts of vascular plants, algae and periphyton growing there. Streams with velocities above 0.60 meters per sec-1 usually have large bare rocks that don’t enable plant growth while streams with lower velocities usually have silt, mud or sand substrates that can support plant growth. Since most of Florida’s springs are lower than 0.60 m sec-1 there are plenty of plants growing there, the only limiting factor for vascular rooted plants are limestone outcrops that only support bryophytes and algae colonies. The type of algae is influenced by light, substrate and velocity, with epiphytic microalgae and benthic mats being commonly found in many spring fed ecosystems (UF, Jacoby).
Streams with high velocity flows will have more periphyton species like low-lying mucilaginous diatoms that can resist being carried away and less species of long filamentous algae. One study on the Weeki Wachee River showed that increased stream velocity correlated with less periphyton growing on the macrophyte plants. Another study on the Ichetucknee River found higher levels of periphyton growing on macrophyte plants in tributary streams with lower velocities (UF, Jacoby).
The rate of flow can influence the thickness of the boundary layer of an aquatic system. The boundary layer can regulate what type of nutrients, dissolved oxygen or free dissolved inorganic carbon compounds are accessible for uptake by the periphyton. In streams with slower moving water the boundary layer is usually thicker, making nutrients and dissolved compounds diffuse of be moved over longer distances. When the water moves faster the boundary layer is thinner and cells can have regular contact with the nutrients and dissolved chemicals that they need (UF, Jacoby).
An equation called Fick’s Law is used when calculating how much the steepness of the concentration gradient across the boundary layer influences the rate of transport.
Fick’s Law is written as;
J = –D ∂∂φχ
J = diffusion flux in moles (m-2s-1)
D = diffusion coefficient or diffusivity (m2s-1)
Φ = concentration gradient per unit length in moles (m-3)
Χ = length of the boundary layer in meters
The concentration gradient (∂φ/∂χ) is decreased in slower moving streams by depletion of nutrients and limits the periphyton’s access to nutrients. Small increases in water velocity less than 0.1 cm/s can help underwater macrophyte plants. Usually the periphyton grows as water velocity increases until reaching a plateau when the shear begins sloughing (UF, Jacoby).
Macronutrients such as phosphorus, nitrogen, potassium and several other micronutrients are needed to enable the growth of periphyton, vascular plants and other algae in streams downstream of springs. Several studies of spring systems in Florida have shown that rooted vegetation and macroalgae termed collectively macrophytes were not influenced by the total concentration of either nitrogen or phosphorus. Another study of five spring fed coastal rivers showed only two had positive relations between nitrates and macrophyte plant growth. The positive results of the Chassahowitzka River samples were later shown to be a direct result of denitrification downstream and rapid nitrate removal, not from uptake by the plants themselves. The same pattern is found in the Homosassa River where nitrates decline sharply downstream despite negligible growth of macrophyte plants. However, this same study shows a positive correlation between soluble reactive phosphorus and growth of macrophytes. Another study on the Chassahowitzka River determined that added phosphorus was responsible for additional periphyton growth more so than nitrogen amendments. Several additional studies show periphyton grow on macrophytes more when given phosphorus supplements than when given nitrogen (UF, Jacoby).
Different species of algae show preferences for different nitrate half saturation constants, the common filamentous green algae (Cladophora) prefers 100-200 ug l-1 while saturation levels for benthic algae in Arizona and Missouri is 55 and 100 ug l-1, respectively. The general consensus is despite preferences in species to nitrate levels that nitrogen itself is not a limiting factor for the growth of periphyton, algae and macrophytes. Nitrogen limitation can happen within a larger algae mat where diffusion rates and nutrient gradients vary throughout the mat (UF, Jacoby).
Half saturation constants for phosphorus were also different among species; green algae Spirogyra were 9-45 ug l-1 while Cladophora was 15-240 ug l-1. The benthic alga mats were from 7-50 ug l-1 while the periphytic diatoms were only 0.6-6 ug l-1. Unlike the increase of nitrogen from runoff, the levels of phosphorus in Florida’s springs remained mostly constant with original levels, though concentrations differ greatly between many spring systems. Though some benthic mats can assimilate phosphorus directly from sediments, it remains the limiting factor to growth for most periphyton, algae and macrophytes (UF, Jacoby).
Competition between periphyton, algae and macrophyte plants is determined by the minimal available component needed, either dissolved nutrients and gasses or light availability. A lower concentration of nutrients with good lighting benefits the slower growth patterns of the vascular plants with developed roots as they can access nutrients in sediments. Algae growth is improved when nutrients are increased as they can harness light more effectively (UF, Jacoby).
Under conditions of eutrophication the faster growing periphyton and benthic algae can overshadow the slower growing vascular plants with roots and thick fronded macroalgae. The overgrowth of benthic algae mats further limits light availability and can eliminate rooted vascular plants and macroalgae from that section of the spring system. According to a study of eutrophication progression done by Duarte, the major point is that the change in the vegetation based on nutrient levels is a sudden one, since the replacement of spring stream vegetation is not determined by nutrient delivery (UF, Jacoby).
When an abrupt change in spring stream vegetation occurs it is not correlated with excessive nutrients and can exist independent of the nutrient levels. Since the research shows independent results between the two factors nutrients and plant growth their studies on Florida spring stream systems indicates that alternative factors besides nutrient levels are responsible for species variety and amount of vegetation. The rate of growth is a factor that is influenced by grazing, since quicker growing species of algae do not invest much energy into protective structural tissues they can be more affected by grazing. Conversely when algae mats bloom in excess they increase respiration and create either hypoxic or anoxic conditions that can kill off the grazing animals. After loss of grazers there is no other factor to limit algae growth and this creates a positive feedback loop that worsens eutrophication (UF, Jacoby).
There are already several examples of Floridian spring stream vegetation altering and having negative impacts on their ecosystem. Certain cyanobacteria such as Lyngbya wollei have increased their populations following eutrophication and have been linked with skin infestations on manatees and possibly human swimmers due to a neurotoxin produced by this species of cyanobacteria. In the case of ecological intervention restoration may take centuries as the fast growing species of algae need to be replaced by slower growing macroalgae and rooted vascular plants, similar to the long term restoration needed to replace similar species of slower growing seagrass (UF, Jacoby).
In Florida over 700 springs and their streams provide habitat to numerous species of flora and fauna that would otherwise not exist in the surrounding pinelands and scrub sand desert ecosystems. Since phytoplankton and zooplankton are not noticeable until they are further downstream the relevant communities for spring systems is limited to benthic species and their trophic food pyramid. The base of the trophic food pyramid for spring stream systems is allocthonous species from outside the spring and autocthonous species from inside the spring system. An example of allocthonous species would include leaves falling into the stream from surrounding species such as longleaf pines or saw palmettos. Autocthonous species include primary producers such as macroalgae, periphyton and rooted vascular macrophyte plants that are dependent upon nutrients within the spring. These autocthonous primary producers in a spring system provide food to primary consumers such as insect larvae, snails and other aquatic invertebrates. The secondary consumers are mostly fish and raptors. Within the Florida spring system the invertebrates were categorized according to function; grazers of attached algae, shredders of coarse plant matter either living or dead, gatherers of fine organic detrital particles, filterers of organic particulates in suspension and animal predation. Among the fish there were specific herbivores of algae and plankton, consumers of detritus, invertebrates or fish (UF, Jacoby).
Within the karst caverns are habitat named stygobiota that exists only within aquifer cave systems and their springs. Within the Floridian aquifer caves one third of the stygobites live in a single cave system and 67% of the taxa are found in ten or less cave systems. This narrow range of habitats results in many of the stygobites being considered rare, threatened or endangered. Some of the endemic spring snails in Florida springs are hydrobiids and pleurocerids with limited ranges, resulting in eight species listed as threatened or endangered (UF, Jacoby).
There are only a few studies on the changes in macroalgae, vascular plants and periphyton and their invertebrate consumers resulting from excessive nutrients altering the vegetation. Two separate studies on the Weeki Wachee and Homosassa Rivers show general results that insects such as mayflies were able to increase their population when there was more dissolved oxygen near spring boils (UF, Jacoby).
The vegetation influenced the type of invertebrate living there, gatherers were everywhere yet were most dominant on bare sediments. Grazers were found on floating mat species such as water pennywort (Hydrocotyle umbellate) and beds of tape grass (Vallisneria americana). Filterers were often found in beds of tape grass yet were not in floating mats. Shredders were common throughout the shallow stream system yet amounted to less than one percent of the total organisms studied. These preferences show that any changes to the vegetation habitats would alter the composition of the invertebrates found there (UF, Jacoby).
Throughout Florida’s lotic systems invertebrates are used to determine the overall ecological health of the system by using two indices; the Stream Condition Index (SCI) in laboratories and the Biological Reconnaissance (BioRecon) in the field. These indices combine number of taxa, specific taxa and percentage or relative abundance of taxa when compared to others. The basis for these indices is that invertebrates often respond consistently to disturbances to habitat, water quality and surrounding land disturbances (UF, Jacoby).
Over a 14 year study on the Suwannee River basin an increase in nitrate concentrations was shown to correlate positively with overall abundance yet negatively with number of taxa, species diversity and evenness. The conclusion reached was that higher nitrate concentrations would increase total numbers while decreasing biodiversity of invertebrates (UF, Jacoby).
The SCI index was applied to nine and four streams in Florida and determined that when nitrate-nitrite concentrations were from 0.02-1.90 mg L-1 the SCI values were very poor to poor in the nine streams and when the n-n concentrations were 0.06-1.60 mg L-1 the SCI values were fair. The SCI habitat ratings and nitrate-nitrite concentrations were less significant (1% and 16% respectively) than the positive correlation between dissolved oxygen concentrations (36%). This shows significant differences between SCI values yet very little variation between nitrate-nitrite concentrations, showing the sensitivity of biodiversity to subtle changes (UF, Jacoby).
The nitrates and dissolved oxygen first alter vegetation and that can affect the invertebrate community which then impacts the next tier on the trophic pyramid, the fish. In a study of four different habitats along Florida’s Wekiva River 40 different species of fish were collected. The ranking of habitat types from greatest mean density of fish was Hydrocotyle umbellate, Vallisneria americana, Nuphar advena and bare sediment. The reasons for the preferences were complex interactions between the chemical and physical conditions of the habitat and the biological and ecological adaptations of the fish species (UF, Jacoby).
Another impact of altered vegetation is on the life stages of aquatic species, as some fish species require the presence of macrophytes and vascular plants to protect their young from predators. Changes in habitat vegetation can alter their growth rate. Macrophytes include mosses, flowering plants, and macroalgae that have higher than average carbon to nitrogen ratios (C: N 20-1,340), having more lignin and cellulose than digestible plant tissues along with unpleasant secondary chemicals to repel most grazers. Since macrophytes are a substrate for periphyton they are also damaged or grazed by animals that prefer periphyton. Grazers are responsible for maintaining the balance between excessive amounts of periphyton that would compete with their macrophyte hosts for nutrients and light and eventually cause eutrophication (UF, Jacoby).
An experiment that excluded caddisfly larvae from grazing on periphyton showed grazed control sections had biomass levels measured in chlorophyll a cm-2 that were 5 – 500 times lower than ungrazed experimental sections. The turnover, measured as oxygen production per unit of chlorophyll a, was five times higher in the grazed control sections of periphyton. A comparison of several related tests showed grazers could effectively reduce periphyton biomass in 70% of the experiments and could alter the physiognomic structures and assemblages in 81% of the experiments (UF, Jacoby).
There is a constant “chemical warfare” type of arms race between the grazers and the vegetation. The amphipod grazer Hyallela azteca is stopped by the extracellular polysaccharide sheaths on Lyngbya wollei. In some tests protozoan grazers consumed benthic diatoms from rates of 4,000 diatoms cm-2 h-1 in systems without macrograzers and 150 diatoms cm-2 h-1 in systems with many macrograzers. Other tests show complex symbiotic relations between the two, such as the chironomid larvae that builds tubes that are used as substrate for periphyton that are then consumed by the larvae. However, increases in phosphorus and nitrogen led to greater periphyton biomass and eventually larger larvae. This began a positive feedback loop as the larvae built larger tubes there was more surface area and thus even more periphyton available (UF, Jacoby).
Other experiments showed that periphyton increased significantly when nitrogen and phosphorus were both added, light was increased and no more grazing. If only light was increased the periphyton decreased production of chlorophyll a cell concentrations. The light increase only test showed an altered assemblage of periphyton as other low light adapted algae were replaced (UF, Jacoby).
Interactions between different trophic levels can influence grazing, such as grazing minnows being driven away by predatory fish would enable algae mats and periphyton to grow. Another study on a lake showed alterations in populations of zooplanktivores and piscivores would cause the growth of gelatinous colonies of green algae phytoplankton. This was altered only when piscivorious fish were introduced and had lowered the population of zooplanktivorous fish enough so the zooplankton numbers were able to increase and consume the phytoplankton algae colonies (UF, Jacoby).
Time and nutrients can interact in complicated ways to increase primary vegetation for the first two years while insect and fish populations don’t catch up until the third and fourth year since nutrients were added. The complicated interactions between multifactorial conditions such as chemistry, temperature, salinity, predation and others ensure that lotic systems will not respond in a linear fashion and will have unpredictable feedback loops and thresholds. Nonlinear responses are part of the eutrophication process when nutrient increases and interactions between conditions eventually replace perennial vascular plants that have sturdy roots with quick growing algae colonies, periphyton mats and phytoplankton. The only generalization about eutrophication and responses to nutrient increases is that it is unpredictable and can have unexpected outcomes. Another factor further complicating interactions between producer plants, consumers and top tier predators is interactions between parasites and their hosts. In one test it was discovered that increased algae led to increased snails and then the parasite trematode Cercariae that caused deformities in large numbers of frogs (UF, Jacoby).
The toxicity of ammonia, nitrates and other chemicals are measured by a concentration that kills half of the organisms being tested over a specific time period, denoted as LC50. According to Florida law the definition of a 96 hour LC50 is a concentration that kills 50% of the organisms in a four day time frame. Two additional terms are used to describe less than lethal endpoints that result in a measurable effect over a specific time frame; least observable effect level (LOEL) and no observable effect level (NOEL). The LOEL is defined as the lowest concentration when a noticeable change is recorded and the NOEL is described as the concentration when a noticeable change is no longer able to be recorded. Sometimes the data used for tests is far shorter than either the life expectancy or the time required to reach a balanced concentration within the organism’s tissues. The steepness of the dose-response curve can require the use of uncertainty factors, with larger factors for steep curves and smaller factors for shallow sloped dose-response curves. Either way, uncertainty factors lower the concentration deemed appropriate for the ecosystem (UF, Jacoby).
The most toxic compound found in watersheds is ammonia, followed by nitrite and then nitrate. Ammonia toxicity is measured by the U.S. Environmental Protection Agency when determining standards for water quality. The EPA also found that ammonia toxicity can be influenced by ionic composition of the water, pH and temperature. The pH related toxicity seems to be a result of combined toxic effects of unionized ammonia and ammonium ions. Temperature is also responsible for the presence of unionized ammonia and ammonium ions, though ionic composition was less relevant (UF, Jacoby).
To determine acceptable levels of ammonia criterion maximum concentrations (CMCs) are used for short term exposure and criterion continuous concentrations (CCCs) are used for long term exposure. Unfortunately when tested in the field the proposed criteria were determined to be inadequate at protecting a species of mayfly in New Zealand from long term ammonia exposure. In Florida the concentrations of ammonia were the single determining factor for the existence of stygobitic crayfish. The criteria is limited yet remains the best option given the conditions, a starting point to determine safe levels of ammonia. The precautionary principle should be applied along with the criteria when determining safe concentrations of ammonia (UF, Jacoby).
The criteria equation is based upon known temperature (T) and pH levels of a specific stream or water body. The acute criterion (CMC) is written in the following equation;
CMC = 1 + 100.277.2504 – pH + 1 + 1309p.H0 – 7.204 (salmonid fish present)
CMC = 1 + 100.471.2104 – pH + 1 + 1508p.H4 – 7.204 (salmonid fish not present)
To be effective a one hour average concentration of total ammonia nitrogen (mg-N L-1) should not be any number higher than the CMC number for more than once on an average three year cycle.
The same variables are used in the calculation of the chronic criterion (CCC) written in the following equation;
CCC = (1 + 107.688– pH + 1 + 10pH – 7.688) • Minimum of (2.85, 1.45 • 10 0.028 • (25 – T))
(Early life history stages of fish present.)
CCC = (1 + 107.688– pH + 1 + 10pH – 7.688) • 1.45 • 10 0.028 • (25 – Maximum of (T, 7))
(Early life history stages of fish not present.)
To be effective a thirty day average concentration of total ammonia nitrogen (mg-N L-1) should not be any number higher than the CCC number for more than once on an average three year cycle. The highest four day average concentration of total ammonia nitrogen (mg-N L-1) should not be more than 2.5 times above the CCC number over the thirty day time frame (UF, Jacoby).
The two most common forms of oxidized nitrogen found in watersheds are nitrate (NO3-) and nitrite (NO2-). Of these two nitrate is the most stable and tends to occur in higher concentrations than nitrite, formed by nitrifying bacteria and usually reverting to nitrate over a relatively short time. Since nitrate is soluble in water it remains in the groundwater or surface water unless denitrification changes it to pure nitrogen gas (N2) and it escapes into the atmosphere or it is absorbed into tissues of vegetation like algae, macrophytes and periphyton (UF, Jacoby).
The two nitrogen compounds nitrite and nitrate are absorbed by vegetation and also taken up by animals through their permeable membranes such as gills in fish or skin in tadpoles and amphibians. The other method of nitrogen uptake is through ingestion where it is absorbed by the intestinal wall in birds and mammals. The gill membranes can transport nitrate through the chloride transport mechanism into the bloodstream and other body fluids where it can become nitrite and can possibly accumulate as a result of hepatic detoxification of nitrite. Nitrate remains a threat in the bloodstream as it can interfere with hemoglobin by preventing it from transporting oxygen to cells, causing cyanosis and tissue hypoxia. The hemoglobin molecule in vertebrates contains a central iron atom that is oxidized by the nitrate causing a condition called methemoglobinemia. The oxidation of iron in hemoglobin disrupts the reversible binding of oxygen. Cyanosis in humans and other mammals from hemoglobin disruption by nitrates is one of the main reasons for blue baby syndrome. In addition most animals are impacted by nitrate as a disrupter of the endocrine system, steroid hormone synthesis, sperm motility and viability, fecundity and development of embryos. Recently excessive nitrate levels were deemed responsible for the decline of amphibians in many watersheds (UF, Jacoby).
For invertebrates nitrate toxicity effects begin as low as 0.23 mg L_1 NO3-N for marine shrimp larvae and lethal concentrations over a 96 hour test are from 62.5 mg L_1 for adult amphipods to above 1,000 mg L_1 for adult snails. Mayfly nymphs that were exposed to a combination of nitrate, nitrite and ammonia showed effects of toxicity at 0.70 mg L_1 NO3-N and caddisfly larvae at 2.2 mg L_1 for nitrate alone. Two generalizations were reached from the accumulated data, that early life stages and freshwater invertebrates were far more sensitive to nitrogen toxicity than were adults and marine invertebrates (UF, Jacoby).
For fish the nitrate toxicity began as low as 1.1 mg L_1 NO3-N for least or no apparent impacts on eggs to above 1,000 mg L_1 NO3-N for impacts on early stages of life. Many species of fish including channel catfish, largemouth bass, bluegill and mosquitofish are impacted by both nitrite and nitrate. As with the invertebrates’ early life stage sensitivity, the eggs, embryos and fry of fish species are more vulnerable to nitrogen toxicity than are adults (UF, Jacoby).
The permeable skin that amphibians use for respiration and hydration also causes them to have elevated rates of nitrogen absorption. This tendency for increased sensitivity to nitrogen makes amphibians excellent indicators of a toxic watershed. The evidence of toxicity in amphibians is visible in deformities such as third limbs and mixed sex genitals and in disruption of feeding, metamorphosis, mating, endocrine activities and other biological processes. The toxicity levels for amphibians are from 13.6 mg L_1 to above 1,000 mg L_1 causing death in embryos in 96 hours and 4.9 mg L_1 to 65 mg L_1 impacting tadpoles. Each species shows varied responses to factors like chemical composition and type of nitrogen compound. The southern toad (Bufo terrestris) tadpoles in experimental pools with nitrate levels of 30 mg L_1 reached metamorphosis faster than controls in reverse osmosis and six days longer than controls in unfiltered spring water (UF, Jacoby).
For reptiles nitrates are also a threat, the American alligator is sensitive to levels as low as 0.01-0.04 mg L_1 NO3-N, with lowered testosterone levels in young males and females and raised estradiol levels in young females. Birds and mammals are exposed to nitrates by ingestion; cattle showed effects of toxicity at 133-220 mg L_1 and began to die when levels reached 221-660 mg L_1. The standard nitrate concentration for human drinking water is 10 mg L_1, out of Florida’s 130 springs 92% were below 2 mg L_1, though in the remaining 8% the levels exceed safety standards and within all springs the toxicity levels can become close the safety limit for brief durations (UF, Jacoby).
An excess of nutrients impact watersheds by increasing toxicity, altering the trophic food web and/or alteration of habitat. Toxicity can range from impacted respiration, altered lifestyle and even death in extreme cases. Certain individuals can develop altered traits from nutrient exposure than could impact their entire population and the trophic food web and surrounding ecosystem. The responses to nutrient excesses are usually unpredictable beyond the expectation that the results will be non-linear. The researchers from the University of Florida recommend that instead of trying to respond ineffectively against unpredictable nonlinear reactions society should try to protect the springs by preventing nutrient excesses from occurring (UF, Jacoby).
In Florida springs and their resulting watersheds eutrophication from excessive nutrients is an increasing problem. The general conclusion is that the eutrophication progression eventually replaces slower growing rooted native vascular plants with fast growing surface floating algae colonies and periphyton mats. Nonlinear responses in stream systems to eutrophication progression can result in unexpected outcomes. Preventing eutrophication by managing nutrients in spring ecosystems would be the most logical human action possible (UF, Jacoby).
Further research into nutrients, oxygen, carbon, light, velocity or stream flow, grazing, algae and vascular plant species, invertebrates, fish and other ecosystem components and their interactions are needed to further determine safe levels under various conditions. Obtain details on spring systems such as total maximum daily loads and minimum flows and levels to be better able to devise effective pollution load reduction goals and watershed management. Samples should be taken at spatial and temporal scales where various components and interactions between them can be isolated or retested for improved understanding. Further studies on macroalgae, vascular plants, microalgae and periphyton are needed to understand nutrient uptake, eutrophication progression and rates of grazing by invertebrates (UF, Jacoby).
Aquifers and Spring Streams Function Best at Fullest Possible Level with Returns to Same Basin
Springs and their streams are unique aquatic ecosystems often surrounded by terrestrial ecosystems and usually are an oasis of crystal clear water with nearly constant temperatures and chemical equilibrium. Springs are described by their shape and volume (basin morphometry), geographical location, flora and fauna. Typical biomass trophic position webs and trophic level pyramids for spring ecosystems are usually stable and very productive unless there is interference from humans and excessive extractions and/or pollution. The report from the University of Florida recognizes the unique role of spring ecosystems and has identified excessive groundwater extractions and increasing nutrients as the two greatest threats to spring stream ecosystem stability. The authors suggest that for peak performance the biological complexity of spring stream ecosystems need greater understanding, monitoring and protections of groundwater levels and quality along with the aboveground ecosystem interactions of springs, seeps and their streams (UF, Knight).
Springs and their streams usually emit groundwater with exceptional clarity and also containing dissolved minerals, nutrients and gasses. The clarity of the spring stream’s water enables light availability to increase and support diverse species of plants and animals that have adapted to specific temperatures, pH levels and dissolved mineral/nutrient content of the spring stream that they are endemic to. The springs of Florida covered in the UF report were around since approximately 15,000 – 30,000 years ago, giving spring flora and fauna enough adaptation time to evolve several unique species of endemics found nowhere else on Earth besides their home springs and streams (UF, Knight).
The twin threats of excessive groundwater extractions and nutrient loading are self-supporting mechanisms that exacerbate and compound one another by enabling growth of opportunistic and invasive species of algae and resulting accumulation of organic detritus. Water quality and clarity are reduced as the spring stream’s velocity runs slow and the invasive and the harmful algae colonies grow (UF, Knight).
Research of spring ecosystems is increasing due to their unique species and stable conditions, resulting in an expansion of the growing field of “crenobiology” derived from the Greek word “creno” (spring). The resulting studies of spring stream ecology are categorized as either reductionist or holistic; the former being the study of one species within the system of greater ecological controls and interactions and the latter being the study of the entire community. To gain a complete understanding of the ecosystem and individual species within the community both holistic and reductionist tests need to happen (UF, Knight).
The study of spring ecosystems on a holistic level represents an accurate portrayal of the community since the external factors that influence structure and function of the spring are more constant in springs than in other ecosystems. The stability of spring ecosystems results in a consistent food web relying on a stable primary producer and less temporal complexity than in other aquatic ecosystems. Springs also show a variety of community structures that respond to the unique chemical and physical factors found in each individual spring. Most importantly the study of spring ecosystems relates to human usage of groundwater and the effects of extractions and nutrient loading on the spring’s biodiversity (UF, Knight).
Springs have clear water with dissolved gasses and nutrients entering streams that support a wide range of biodiversity. The productivity of spring ecosystems is based mostly upon light available for photosynthesis and slightly influenced by nutrient availability and temperature. Within Florida the numerous spring ecosystems have existed from 15,000 – 30,000 years and have evolved plants and animals that are adapted to the specific conditions of each individual spring (UF, Knight).
Collectively the studies on spring ecosystems in Florida have shown the two greatest negative impacts come from excessive groundwater withdrawals and pollution from nitrates. The results are reduced flow, eutrophication and overgrowth of destructive algae species. Research into spring ecosystems began in the 1950s when Odum and Whitford reported the constant factors of temperature, chemistry, discharge (rate of flow) and dissolved nutrients and gasses were nearly always the same for one spring yet almost always different in another (UF, Knight).
Spring ecosystems can be measured in several ways; the global or regional scale, springshed scale and spring scale. The global or regional scale takes into consideration the latitude, climate and other factors such as human influences. The springshed scale includes the local land containing the aquifer that feeds the spring and data on subsurface conduits, potentiometric levels and rate of flow. The spring scale includes the type of algae, periphyton and vascular plants growing around the spring (UF, Knight).
The primary contribution of energy into spring ecosystems is from the sun, using photosynthesis to create energy and release heat as entropy of conversion. During a study of Silver Springs, Odum recorded that only 24% of the total solar energy input was absorbed by the primary producer plants, with only 5% of that amount actually converted into gross primary production. However, the low number of photosynthetic efficiency found in spring plants is relatively high when compared to most other plant ecosystems including those cultivated by humans. The photosynthetically active radiation (PAR) is the small section (400 – 700 nm) of a greater range ( 1) or heterotrophic (P/R 6 ug chl-a cm-2. Other factors to consider are when higher elevation streams that do not normally have much plant material due to cooler temperature have even slight algal growth it could be considered excessive and eutrophic despite having chl-a numbers that classify them as oligotrophic (UC Davis, CWAM).
Biotic integrity for periphyton taxonomy includes several factors used by the EPA as measurements. The richness of species, genus and division refers to the number of each category per sample and can be an indicator of nutrient enrichment in an otherwise nutrient limited system, biotic integrity or pollution. The percent community similarity shows assessment between sites based upon number of species in the community. The Shannon Diversity Index is the combination of the evenness of distribution of individuals among taxa and the number of species. The Pollution Tolerance Index (1-3) with 1 being tolerant and 3 being intolerant is calculated with this equation;
PTI = Sum(nCtC)
nC = number cells counted for species C
N tC = tolerance value of species C
N = total number cells counted
The percentage of sensitive diatoms is the sum of relative abundances of all species that are unable to tolerate pollution, useful in low productivity streams where other measurements can underestimate the degree of pollution. The percentage of Achnanthes minutissima can show recent disturbances as this species is first to grow there, especially frequent with acid mine drainage. The greater percentage of this species correlates with the worst disturbances. The percent of overall live diatoms shows sediment deposition on algae or of older assemblages. The percent of aberrant diatoms have abnormal patterns in their frustules and can indicate heavy metal contamination. The percent of motile diatoms indicates numbers of mobile genus such as Navicula, Nitzschia and Sunrella and shows signs of siltation as these are able to crawl above silt while other non-mobile species are suffocated. Other measurements include relative abundance of percentage of species of genus X and include information on the ecological needs by percentage of species that are acidobiontic, acidophilic, alkalibiontic, alkaliphilic, halophilic, mesosaprobic, oligosaprobic, saprophilic and eutrophic. This is similar to the Simple Autoecological Indices (SAI) that show habitat preferences and relative abundances of various taxa in a given sample as an indication of prevailing conditions of the ecosystem. Another measurement is the Weighted Average Indices (WAI) that compares the relative abundance of diatom taxa with maximum abundance values under best possible growth conditions based upon prior scientific research. Finally there is a test to determine if there is impairment of ecological conditions, a result of the deviation from a test site to a normal site using SAI and WAI data to measure and contrast differences (UC Davis, CWAM).
Using some statistical measurement tools can obtain results for community composition in each location, dry and organic mass of sampled periphyton and amount of chlorophyll-a per sampled section. The California Stream Bioassessment Protocol shows how the Student t-test and Analysis of Variance (ANOVA) can be used to compare two sets of data, such as one site upstream and one downstream of a pollution source. The major focus of stream status is the differences between sampling locations and times and also between standard normal references and study sites being tested. Three additional questions can help obtain these results with greater accuracy;
Are changes if stream velocity flow or temperature responsible for algal community structure differences? Try Chi-square test (large N) and Fisher’s exact test (smaller N) for answer.
Are there impacts from discharges? Sample above or below the discharge location and then compare percentages of different species of algae that are sensitive or tolerant to pollution. Prior to a t-test comparing samples and sites the data needs to be converted into an arcsin or logarithmic transformation.
Are other factors such as nutrient input, reduced shade cover, higher temperatures or reduced flows causing algal blooms? This can be found by measuring biomass changes or finding chlorophyll-a per unit area of benthos. Continuous measurements or quantification data such as biomass from one site or sample can be compared to others using a Student t-test or between multiples samples and sites using an ANOVA test. For longer term research a trends analysis can be done (UC Davis, CWAM).
Other non-quantitative basic monitoring methods include a photo narrative. First identify what type of impact being studied; whether the pollution is from a fixed or diffuse source and the range of it. Next select above three samples at each chosen site to get an understanding of variation within algae species. Greater number and random distribution of samples and sites will ensure there are enough representatives from different microcosms along the stream, such as riffles. Describe the ecosystem landscape (riparian vegetation, channel substrate and watershed steepness) being sampled, record water temperatures at different sites and any abnormal characteristics that would induce algae growth such as roads, houses or logging. Take photos of the channel bottom throughout early spring to late fall at fixed locations with several per site and always from the same perspective to track any changes in algal growth. Some photos should be reference sites to compare with what is considered normal if this is possible, though with lowered water table the entire stream will become abnormal. Then a before and after photo sequence will need to be taken to show differences resulting from lower stream velocity. These qualitative measurements are useful to show when new or excessive algal growth begins and what the water temperature was before and after the event (lowered water table and stream velocity). Other details to be photographed and recorded include the peak of algal growth, when the algal growth dies off and the presence of filamentous forms different from algal growth under normal conditions (UC Davis, CWAM).
Some minimal requirements to ensure good data quality are to have at least over three random sites for sampling, with the greater the amount of sites the less chance for localized abnormalities. Some non-random sites can be chosen to show differences in before and after changes to groundwater table and flow velocity occur. Timing along with seasonal growth spurts taken into consideration is critical to accurately measure samples for different types of algal species growth responses prior to, during and after flow reduction. To ensure correct identification of algal species a professional taxonomist may be needed (UC Davis, CWAM).
To ensure the succession of the trophic food web pyramid from algae to spring snails to frogs and fish to snakes and eagles and even humans there needs to be monitoring of the spring flow and algal conditions. It would be extremely foolish to expect that the SNWA pipeline would be able to extract billions of gallons of water per year without lowering groundwater levels and reducing the spring velocity when current local extractions sometimes also reduce spring velocity. Local extractions are about as much as the aquifer and springs can handle and this needs to be carefully monitored to avoid stressing the spring snails. The role of the spring snail is vital to ensure the health of the entire ecosystem and is the first indicator species of imbalances caused by eutrophication and excess algae growth. However, water quality, temperature and spring velocity are all crucial factors to the spring snails performing their roles as primary consumers of periphyton and algae. Loss of spring snails from their habitat will result in excessive algae and periphyton growth and eventually eutrophication. The most effective way to maintain good spring velocity and water quality to enable the spring snails’ algal and periphyton consumption is to prevent excessive aquifer withdrawals by banning the proposed SNWA pipeline and closely regulating local extractions. Supporting a spring stream ecosystem with enough biodiversity and trophic levels requires maintaining aquifers at their highest possible levels.
Good groundwater level maintenance requires a reasonable process to allocate permits that do not amount to a greater or equal number than the average rate of recharge. Aquifers function best at ensuring regular spring flow when they are at their fullest levels. The water permits issued should be less than the rate of recharge to prevent over extractions of groundwater during seasonal droughts. Water should remain in the basin from where it was extracted and irrigation water should be returned to the same aquifer by percolating it down through alluvial fill.
Urban regions that rely on perpetual development need to refocus on recycling and conservation in their own district instead of trying to heist water from distant rural districts. There are several assumptions that modern humans make when comparing their economic system with their physical environment. One faulty assumption of many modern humans is that their economic system’s so-called need for constant growth as development can somehow dictate and transfer this need onto the physical ecosystem. It seems as if the residents of urban regions in the desert believe that they can continue to add buildings and humans to their existing population indefinitely into the future and somehow the water will keep coming from somewhere with no adverse effects.
While contemplating the extinction or extirpation of spring snails in exchange for more golf courses and suburban housing developments our society should ask ourselves and our representative leaders some questions. Why does Las Vegas feel that in order to “survive” they need to continuously increase their population and water intake until they are approaching cities like New York and L.A.? Is building another 100,000 homes at the Coyote Spring housing development really necessary for anyone’s survival outside of outstanding economic profits for the Wingfield Company and their benefactors? How many more casinos and housing developments are needed for the survival of this type of economic system that has made itself addicted to perpetual development forever sprawling out away from the urban core?
Recent mythologized ideas of economic success from perpetual suburban sprawl development and water grabs do not take into consideration the needs for ecological stability and the benefits that a healthy spring stream ecosystem provides humans. Early humans indigenous to the Great Basin have lived in harmony with the spring fed ecosystem for thousands of years. Prior to recent settlement and well drilling indigenous people like the Shoshone, Paiute and Goshute would collect their drinking water at the source of the spring and harvest the bounty of animals including many endemic fishes that thrive on the spring snails. The indigenous perspective in ecology is focused on giving and receiving and not taking more than what is needed. This view values the water at the source point of the spring where other beings can partake in the emergence of living waters and also understands that the spring waters the vegetation that feeds the snails that feed the trout. Finally the indigenous perspective gives thanks and praise to the spring, plants, snails and trout when they harvest the fish for cooking. There is no dividing line between water, plants, snails, fish and humans when it comes to ecological processes other than the levels of the trophic pyramid. This spring ecosystem’s natural food services to humans would likely continue for thousands of years provided there are no excessive extractions from humans as the rate of refill isn’t as much as it was when the aquifer was formed.
There is constant yearly renewal of spring ecosystems from the upwelling of groundwater that can support itself indefinitely under current climate conditions. However, dropping groundwater levels from SNWA pipeline extractions cannot support this spring ecosystem’s yearly renewal and along with the spring snails other species will also suffer from losses of the springs, including the human population. Though all humans will suffer a loss if the spring snails become extinct, some humans will feel worse than others about this tragedy. It also appears that certain humans and their corporations like Wingfield Co. will benefit enormously from the construction of the SNWA pipeline regardless of the damages it will predictably create once groundwater levels are lowered from excessive extractions.
Political and Financial Motivations for SNWA Pipeline Includes Development of Coyote Springs
Political and Financial Motivations for SNWA Pipeline Includes Development of Coyote Springs
The initial idea for the SNWA pipeline was supported by two powerful developer partners from the Wingfield Holding Company. Throughout the years of listening to SNWA pipeline public relations propaganda, it becomes clear that the case being made for this infrastructure is coming from developers. There are significant benefits to developers especially when the land prices along the pipeline route are far less than within the urban core region. The question for developers was only “where will the water come from?” not “what will happen to the wildlife in the place where the water will come from?” The concern for the developers is to get access to aquifer water with their pipeline and then ride up the U.S. 93 on the coattails of the initial proponent and beneficiary of the pipeline.
The initial financial supporter of the SNWA pipeline was Mr. Harvey Whittemore, a known developer, lobbyist and casino owner. Currently he is involved in a legal feud with his partner in the Wingfield Nevada Holding Company; one Mr. Albert Seeno based out of Contra Costa County, CA. Since the courtroom feud the Coyote Springs development locatesd on U.S. 93 and NV 168 is under ownership of Mr. Seeno, though the initial planner was Mr. Harvey Whittemore. Both partners are megadevelopers who had joined forces to build the Coyote Springs “city in the desert” while quietly financing the nearby SNWA pipeline so that they were ensured a steady supply of water. Since they purchased the land for cheap, the potential to retire as multimillionaires from the total 159,000 homes with golf courses and casinos was not ignored by these developers from Wingfield Company.
The initial purchase price paid by Whittemore to the Aerojet-General Corporation for the 43,000 acres of land at Coyote Springs was $15 million in 1998. When compared to the 1,710 acre Kyle Canyon Gateway development that is now in foreclosure with permits for 16,000 homes purchased from the BLM auction at $510 million, price is the most obvious difference. According to Restrepo consulting group, Whittemore’s advantage with Coyote Springs is the lower land prices found outside of the higher priced Las Vegas Valley (Schoenmann).
It would only require enough water to last for twenty years until they could retire safely before the lawsuits started from Coyote Springs homeowners without water and indigenous tribes, ranchers, and environmentalists who would witness the dried up spring streams as predicted by many scientists decades earlier. Considering the past history of the Wingfield Co. with the FBI and other illegal scams, it isn’t doubtful that the SNWA pipeline is just another racket for these two real estate tycoons.
The FBI investigation of Mr. Whittemore’s Wingfield Nevada Holding Company uncovered many details, such as that they had paid lobbying firm R&R Partners $70,000 per month over a five year period as reported in the Las Vegas Sun. In 2004 Mr. Whittemore loaned $250,000 to lobbyist Pete Ernaut. In his position at R&R Partners Mr. Ernaut advised Sen. Ensign, Gov. Sandoval and other Republicans. In a lawsuit against Whittemore by Wingfield partner Mr. Albert Seeno, it is mentioned that Whittemore forgave the loan (Schwartz).
Some of R&R Partner’s lobbying was for the 43,000 acre, 159,000 home Coyote Springs development located 50 miles north of Las Vegas on the Clark County border with Lincoln near Moapa at the intersection of U.S. 93 and NV 168. The Coyote Springs project was a focus for Mr. Whittemore’s team of lobbyists for many years, as constant cash donations were available for distribution between 2004 and 2010, amounting to $600,000 total taken from Wingfield Co. In 2007 Senator Reid received $124,200 from Whittemore in return for him looking the other way when his development related activities violated environmental laws. The massive plans for Coyote Springs required Whittemore to seek a partnership with another megadeveloper and casino owner, Mr. Albert Seeno Jr. in 2004. They remained partners until the recent lawsuit filed on January 27, 2012 by the Seenos against the Whittemores that included allegations of the Whittemore’s lobbying at the Wingfield Co. expense and without consent from the Seenos. This was followed by a countersuit by the Whittemores that alleged threats were made by Mr. Seeno against them (Schwartz).
During this time R&R Partner CEO Billy Vassiliadis admitted that they worked as a retainer for Coyote Springs, with their contributions of $70,000 to politicians being far above the average $25,000 donations made by Nevada’s largest corporations during a regular legislative session. According to Mr. Vassiliadis his job included public relations, research, government affairs and more intensive work than usual (Schwartz).
As the FBI investigation of Wingfield Co. proceeded, it became public knowledge that there were charges pending for illicit lobbying and campaign contributions. Though it was not specified what the lobbying money was related to, it would be likely that a few more favors and requests for state regulators to look aside when it came to approval of the SNWA pipeline were coming down the pike. Certainly some imaginary mitigation measures to make up for spring snail extirpation approved by Senator Reid would win Wingfield’s favor for another election and support the legal services of his son Rory Reid. However, the gig was up thanks to the work of some diligent field agents and the developer’s favorite politicians needed to dump their dirty money as quickly as possible. By effectively investigating and prosecuting real estate political lobbyist scams like the Wingfield - SNWA pipeline plot the FBI could be considered to also be performing “eco-saboteur prevention” by slowing recruitment of future Earth First!ers along a 300 mile linear training ground in the Nevada desert.
Following the Las Vegas Review-Journal articles about the FBI investigation of the Whittemores’ lobbying, several of the politicians who accepted the donations, including Senator Harry Reid and Rep. Shelley Berkley, gave them to charity. Senator Dean Heller gave the entire $27,000 sum he received from Whittemore since 2008 to charity. Some of these were called “conduit contributions,” that reimbursed people after they made a “suggested” donation (Ralston).
Senator Reid supported and verbally praised Mr. Whittemore’s proposed “city in the desert” Coyote Springs project since 2006 after receiving some large conduit contributions nearing $100,000 in a single day to Senator Reid’s campaign coffers from him. Throughout the years under the guiding hand of Sen. Reid the Nevada State Democratic Party also received large sums from Whittemore, yet they currently claim that there was no violation of law and thus are keeping the money (Ralston).
Besides the FBI investigation of Wingfield and Whittemore for illegal conduit campaign contributions, there are many questions about the Coyote Springs Land Co. accepting money from their partner Pardee Homes in relation to the Coyote Springs development on U.S. 93. Some rather bizarre circumstances have emerged with the “pie in the sky” concept of Coyote Springs as a city in the desert with no locally available water source outside of the future mirage of the SNWA pipeline. In many ways the Nevada sequel to the Owens Valley water grab that occurred nearly a century ago rests upon the shoulders of the two gentlemen from Wingfield and the other smaller developers that got sucked into their real estate Ponzi scheme based upon plotting to steal aquifer water with the SNWA pipeline.
The Seeno lawsuit against the Whittemores state that since the 2003 several purchases made from Whittemore in the Wingfield Nevada Holding Company had discrepancies in their financial records. One of the purchases involved in the Seeno lawsuit includes Coyote Springs Investment LLC and its sister company, Coyote Springs Land Co. LLC. These two corporations are also involved in legal disputes with their partner Pardee Homes about the Coyote Springs project on U.S. 93, including allegations that Whittemore accepted $1.32 million in lobbying money from Pardee. The suit states that Wingfield’s success is based mostly upon this complex multi-million dollar transaction between Whittemore and Pardee and that further embezzlement of Wingfield funds for Whittemore’s personal lobbying occurred against the Seeno’s knowledge or consent (Green).
Whittemore countersued the Seenos and claimed that $20 million borrowed by Whittemore from Seeno was then used to encourage Whittemore to turn over assets and to have Whittemores removed from Wingfield Co. Whittemore also alleged that Seeno made death threats against his family, and attempts to remove valuables from a safe in their home. The Whittemore suit also claims that the Seenos are attempting to "intentionally devalue the assets of Wingfield or claim fraud by the Whittemores, especially at the Coyote Springs development, so that they can improperly claim tax benefits to the IRS and receive huge tax write-offs in the hundreds of millions of dollars to be offset by gains in other Seeno companies" (Green).
The effects of the Wingfield’s lobbying effort pay off by enabling the Nevada state regulators to possess the unique human ability of selective hearing. This type of listening skill can be rewarding to those who are able to afford it, as all who are unable to pay the lobbyist’s fee will discover that their pleas fall on deaf ears. Researchers from elsewhere in the Milky Way Galaxy are as of yet confounded by this strange human ability of money influencing the effectiveness of a state regulator’s ability to hear!
In 2008 Nevada State Engineer Tracy Taylor gave Whittemore’s Coyote Springs a permit for 9,000 acre feet from Lake Valley in Lincoln County for 25,000 homes over 25 years from an application submitted in 2005. This was accomplished by Whittemore buying Atlanta Farms and pumping 12,000 acre feet from there to Coyote Springs via a pipeline constructed by the SNWA. Taylor then stated that an additional 2,300 acre foot permit would be granted if there were no visible negative effects or suppression of potential for development in the basin where the water is being exported from. When officials from White Pine County pointed out that 669 acres of agricultural land was in their county and would lose $40,000 in tax revenue, they were ignored by Taylor (Ryan).
When planning for Nevada’s future we should bear in mind the choices and outcomes of water usage and transfers in other drought prone regions of the U.S. Since the Owens Valley Water Grab 100 years ago in California ended up being unnecessary for L.A. and mostly benefitted a few San Fernando Valley real estate developers and water officials who concocted the idea for the aqueduct, many other water grabs have occurred and many more are being planned.
A Tale of Two Texas Towns and Their Opposing Water Usage Choices
An article in Salon.com describes a tale of two large “towns” in Texas and their choices in water usage and acquisition. Both San Antonio and Dallas exist in nearly the same semi-tropical climate with almost the same yearly rates of precipitation. The different choices made by these two towns are what determine their overall water situation today.
In the ‘90s San Antonio was facing a lawsuit from the Sierra Club as the city was draining their local Edwards Aquifer, home of the endangered Texas blind salamander. Following a few years of a culture war, the general consensus in San Antonio was for conservation, and water usage went from 200 to 130 gallons. Even in drought conditions, San Antonio is not looking elsewhere for any additional water as their conservation and recycling programs are sufficient.
However in Dallas water usage increased by 35% from 1980 - 99 and that city is now desperately attempting to heist water from their neighbors in eastern Texas and Oklahoma. “It’s not that they need the water to survive. What they want is to destroy our wildlife so they’ll have enough water for their grass.” Clearly Las Vegas is at a fork in the road and choices for water usage will determine the economic viability of the city and the people who depend upon financial stability and can live without lawns. The pathway Dallas is on trying to grab water from Oklahoma is an expensive one with no end in sight.
Long term Alternatives to SNWA Pipeline for Improving Las Vegas Water Emergency Storage Potentials
It is important to note that this section is not truly needed as the water pipeline proposed by the SNWA is not necessary either. In some ways the author is falling into the public relations trap set by the SNWA that claims “Las Vegas cannot survive without the pipeline from the Snake, Delmar, Cave and Spring Valleys’ aquifers.” There really is not a need for additional water for Las Vegas outside of their current allotment from the nearby Lake Mead on the Colorado River. However, to catch the SNWA in a lie is too priceless an opportunity to pass up, so the author would like to show why this SNWA pipeline is a colossal lie.
IF Las Vegas truly needed additional water, THEN the planners at SNWA would want a long term reliable source of water. This is a true statement IF the SNWA planners were honest humans. However, IF the SNWA planners are NOT honest humans THEN the first sentence is NOT true. Since Las Vegas does NOT need additional water, THEN no long term water source is needed. The SNWA planners are not under any real pressures to build the pipeline besides the personal financial gain made by distant developers who want to build on cheap land far north of the urban core of Las Vegas.
The reason that the first sentence is untrue is because it is self-evident that the proposed SNWA pipeline is unsustainable in the long term and the aquifer level will drop significantly before a decade is over.
Since Las Vegas did not truly need the pipeline the loss of the aquifers will be noticed by the gullible Coyote Springs homeowners who will need to purchase their water elsewhere or head for greener pastures. The Wingfield Co. tycoons Whittemore and Seeno can fight amongst themselves who gets to die the wealthiest after they retire as dual billionaires. The water planners from the SNWA will retire as wealthy bureaucrats who enabled the Wingfield Co. to follow through with the water heist.
One reason the author is convinced that the SNWA is making false statements is that many other options are available IF Las Vegas actually needed the water. Providing an explanation of alternative means of water acquisition is also a tool to show that less expensive and more reliable options are available, especially if used in conjunction with one another. These methods are not a bad idea to implement for long term water acquisition from local rainfall and improved retention of region watersheds including Las Vegas Wash. Other long term reliable options would include a long distance pipeline from truly flood prone regions like New Orleans and surroundings, who are actually saying “Take our floodwater, PLEASE!” instead of trying to squeeze the last few drops out of the Snake, Spring, Cave and Delmar Valley’s dwindling aquifers in the face of ever growing resistance. The author wishes to acknowledge that SNWA General Manager Mulroy also came up with the idea for the pipeline from the Mississippi yet seems to have abandoned it in favor of the closer yet far less reliable Nevada aquifers. It would be far more successful for the SNWA to pursue transferring water from the flood prone regions of Louisiana with the gratitude of frequently flooded New Orleans residents instead of fighting the Goshute Nation, ranchers and environmentalists over the dwindling aquifers of Nevada.
In order to protect the spring snail and their ecosystem there needs to be protection for the Nevada aquifers from excessive groundwater extractions such as the proposed SNWA pipeline. There are certainly many locally based options that do not require draining distant aquifers, though these choices would not pass directly past the Coyote Springs housing development as the proposed SNWA pipeline would. There is also potential for other developers to attach themselves to the SNWA pipeline near the Coyote Springs project and increase the pattern of cheap land purchases and sprawl along the pipeline’s length. The 300 mile pipeline’s proximity to a potential housing corridor does correlate with the desire of developers to have their promises of water fulfilled by SNWA General Manager Pat Mulroy. Her nickname of “Pipeline Pat” was earned as a result of her intense devotion and pursuit of the pipeline as the only possible way that Las Vegas could survive without everyone “dying of thirst” according to SNWA advertising. Despite frequently and consistently being made aware of numerous other options for improved local water retention, Gen. Mulroy relentlessly pursues the pipeline from the northern Nevada aquifers.
However, SNWA General Manager Pat Mulroy other idea rarely discussed in public is worth further examination. She has suggested moving floodwater from the lower Mississippi River to Las Vegas. While the distance is considerably further than the Nevada aquifer, the quantity of water available is far more reliable and in much greater quantity. The potential to collect floodwater during heavy rains would benefit people living along flood prone rivers while refilling groundwater and cisterns beneath Las Vegas. The water balance during storm events is usually heavily in favor of those being flooded, and transferring some of this excessive rainwater to desert regions could be applied on a national level.
The water transfer would be a simple procedure, adding a catchment basin along the setback levee at intervals of several hundred feet. A setback levee gives the river channel more width to expand and enter a natural floodplain. As the river spreads out in width the velocity slows and the threat of flooding is greatly reduced. During severe storm events whenever floodwaters rise to avoid additional pressure on the setback levees a switch can open the gate at the edge of the floodplain to a spillway leading into a catchment basin. Following some basic filtration of suspended sediments the floodwater can be pushed into a pipeline during these yearly weather emergencies.
To enhance the benefits of constructing such a long distance pipeline a magnetic levitation or “mag-lev” train can be on top of the pipeline. The water traveling through the pipeline needs to be pumped along the distance with or without carrying any additional mass. By inserting some hollowed out metallic paddleballs made out of magnetite the water would push these magnetic paddle balls along the length of the pipeline. These magnetic balls would attract metal bars attached to the sides and below the mag-lev train that would be pulled along with the metal balls inside of the above ground pipeline. The mag-lev train uses opposing magnets to levitate above the surface of the pipeline and does not lose any energy to friction besides wind resistance. The pipelines would combine the energy needed to move floodwater from the Mississippi to Nevada with several other drought prone cities along the way.
Once the water arrives at the final destination, the pipeline will be emptied into aquifers and below ground cisterns in Las Vegas for future use. The mag-lev train timed to leave along with floodwater pulses can help people who wish to voluntarily evacuate a region that is suffering from stormy weather. After arrival the pipeline will be filled with locally grown jojoba oil to move the metal balls and the mag-lev train back to the original start position in New Orleans. The jojoba plant is a drought tolerant native of the Sonoran desert that produces oil useful for industrial lubricant, it could be grown in large quantities without using excessive water as do other crops.
While this seems like an expensive project, our society needs to weigh the long term benefits of floodwater moving from easily flooded regions to drought prone regions with extractions from aquifers that only cause further drought over the next century. Though a long distance pipeline and mag-lev train from New Orleans to Las Vegas will be expensive, yearly flood repairs and consequences of droughts are also expensive over the span of a century. Another factor to consider for the long term is that global warming will likely be raising sea levels over the next few decades and low lying cities like New Orleans will be vulnerable to greater storm surge flooding from rising tides. Unlike the aquifers of northern Nevada, regions like southern Louisiana will always be having many days of excessive amounts of floodwater that will need to be removed from the region. Having infrastructure to move floodwater away from New Orleans and surrounding low lying regions that also pulls along modern mag-lev trains will not be something the future generations will regret having built as sea levels continue to rise alongside gasoline prices.
The mag-lev train on top of the floodwater pipeline would begin in New Orleans and end in Las Vegas with stops in San Antonio, Austin, El Paso, Tucson and Phoenix including several other drought prone cities and towns along the way. Once it is implemented the “Mag-Lev Floodtrain” can prevent droughts in deserts and flooding along rivers indefinitely with some minor maintenance to the infrastructure. Extensions to Miami and other flood prone cities can be made after the main line is completed.
The concept of moving floodwater to drought prone regions from flood prone regions is also being applied in other nations throughout the world. If SNWA General Manager Pat Mulroy would focus her creative energies on making the mag-lev train and floodwater pipeline a reality instead of squeezing every last drop out of nearby desert aquifers she could begin an international trend of floodwater transport to drought regions. If the mag-lev floodwater pipeline is put to use throughout the entire U.S., the terms “flood” and “drought” may become obsolete to everyone in the future except historians.
The floodwater concept of settling and catchment basins for flood prone rivers would be limited by precipitation rates and mostly be directional from regions with higher rates of precipitation to those with lower rates. Even drought prone regions have local rivers that often flood during monsoonal summer thundershowers with massive amounts of precipitation in short intervals. Unlike the slow and steady rise from long term rain events in the Midwest and other temperate climates, the desert southwest experiences sudden rises in rivers as flash floods. Every drought prone region should implement the same settling and catchment basins behind floodplains and setback levees to capture floodwater from their own rivers to prevent flash flooding from summer monsoon storms and capture and filter floodwater for storage in local aquifers and cisterns.
Widening of river channels by using setback levees is another way to both prevent flooding and to recharge aquifers during storm events. Most rivers in developed areas are channelized, making their banks closer to one another than under natural conditions. The width of riverbanks from one another is what determines how much water can pass downstream and at what speed. Narrow channelized riverbanks force the water to flow faster at a higher velocity than wider channeled natural riverbanks. During heavy rainfall and greater water pressure, the levees can be overtopped and compromised due to the constricting of the increasing volumes of water.
Setback levees can alleviate the pressure from additional volumes of floodwater by giving the river more surface area in the channel to spread out over. As it spreads out over the extra width of floodplain the floodwater can percolate downwards from gravitational pressure during and after the flooding as small ponds and oxbow lakes will continue to infiltrate trapped floodwater into the groundwater. In addition to providing beneficial habitat for wildlife, the surface floodwater water filters through gravel and infill before reaching the alluvial aquifer beneath the river floodplain. Under current conditions of narrow channelization this floodwater enters residential or business districts and eventually returns to the watershed as polluted runoff.
Several flood prone regions tried setback levees as a long term solution against the frequent devastation of seasonal flooding. In many cases setback levees and river channel widening has become a bipartisan issue, as in Missouri where Republican Senator Kit Bond has teamed up with the environmentalist organization American Rivers for the mutual goal of building setback levees along the Missouri River. The benefits of widening the channel of the Missouri River with the newly constructed setback levees includes enhanced habitat for endangered wildlife like the sturgeon, reduced flooding and renewed floodplain groundwater recharge. According to Andrew Fahlund from American River, “The river needs more room to move.” (STL Today)
The flood of 1993 along the Missouri River totaled $12 billion in damages. According to Democrat Rep. Chris Kelly; “In 200-plus years of history, we've learned one thing about the river, iIt will flood. So why do we keep tempting fate?" Unfortunately the wise words of Rep. Kelly are not heeded by all, as there was already $2 billion invested in development along the flood prone bottomlands since the last major event of ’93. This type of development in floodplains only postpones the inevitable, as taller levees are also vulnerable to failure (STL Today).
According to Richard Opper, former head of the Missouri River Basin Association, drought years such as the one from 2000-7 can cause river states to fight over water yet during flood years everyone pulls together in unity (STL Today).
The social unity of a flood crisis should also work for wanting to build a national infrastructure of river floodplains restored with setback levees and catchment basins for transporting floodwaters to drought prone regions by pipelines. Other nations like India have begun the process of transporting floodwater from upstream away from populated regions by using canals. The use of canals in floodwater transport requires elevation decrease and this is not possible across the U.S. with regards to bringing it to drought prone regions that are at higher elevations than the frequently flooded lowlands and even the sources upstream. Several nations such as India and some western states within the U.S. have already implemented some type of floodplain expansion or floodwater transfer system or both.
In India A.C. Kamaraj and the National Waterways Development Technology (NAWAD TECH) group are attempting a program to collect floodwater for storing and distributing to places suffering from drought within the Tamil Nadu region of India. To accomplish this they are creating a web of interlinking canals with smaller dams no larger than 25 meters on the upper reaches of rivers to divert floodwater along a horizontal plane nearly 250 meters above sea level. "The salient feature is that the large rivers need not be linked at the lower reaches, where the river is wide. Instead, rivers are linked in the upper stretches where they are connected with their tributaries." The goal of the Tamil Nadu Smart Waterways Project (TSWP) is to collect excess floodwater to be redistributed to the most sensitive drought prone region as needed. Regular river flow is not collected, only during times of flooding is the water removed from the rivers (Sivaraman, TOI).
The San Antonio River Improvements Project (SARIP) is restoring the original meandering curves to their river to enhance the natural slope building mechanisms of fluvial geomorphology. This science relies upon the river to correct itself as needed and build gradually sloping banks along its’ natural course, unlike the channelized concrete rubble that was creating steep sides. The river’s natural sloping banks will also be seeded with native grasses and understory species to enhance habitat for wildlife. The restored riverbanks will be connected to the San Antonio River Walk and other pathways leading into the greater downtown region, providing a boost to local businesses from increased recreational activity (SAR).
There are often severe imbalances between areas receiving excessive precipitation that are dealing with resulting flooding and other areas without enough precipitation dealing with drought. Transporting floodwater from areas with high rates of precipitation to habitually drought prone regions is only limited by the weight of water at 8.3 pounds per gallon. However, the concept becomes more practical despite transportation costs when looking at the natural tendency for some places to receive excess precipitation on a yearly basis. If designed properly a floodwater conveyance system will last for decades and provide relief from flooding and drought simultaneously (Borenstein).
One obstacle noted with floodwater conveyance is that pipelines cannot be moved each year to wherever there happens to be extreme flooding, as this is still unpredictable outside of a larger region that may receive above average precipitation. However, this can be surmounted by transporting water with conveyance devices such as large bags like the “Spragg Bag” or even rail car transport. The initial investment in floodwater conveyance will be rewarded by long term savings from unneeded flooding disaster relief funds. This is one idea that SNWA General Manager Pat Mulroy may find worth pursuing, "One man's flood control is another man's water supply. Doesn't it make you want to think about a larger distribution that helps both? That's the crazy part of this. It's a win-win. There's no loser." (Borenstein).
The U.S. Army Corps of Engineers and Yakima County are building a setback levee along the Yakima River in Washington following a 2011 flood event that damaged an existing levee beyond repair. This requires some additional changes along bridges and existing roadways, though when completed the Yakima setback levee will “reconnect 20 acres of floodplain at the setback site, providing an opportunity for high flow events to establish side channels and natural depressions”, according to Yakima Authorized Levee Rehabilitation project manager Brian Nelson (Dredging Today).
Washington seems to be setting records in the amount of rivers that now have setback levees. In Pierce County on the Puyallup River a setback will restore 53.8 acres of floodplain habitat. The original levees restricted the channel and prevented natural floodplain functions from occurring to the detriment of the ecosystem. The new setback levees will benefit endangered salmon, steelhead and other riparian fish species by enhancing their habitat (Wildlife Recreation).
In California the Feather River Setback Levee project won the American Society of Civil Engineers (ASCE) Flood Control Facility Project of the Year award in 2009. This six mile long setback levee is the longest setback levee in the state. This setback levee provides 40,000 residents of southern Yuba County with 200 year flood protection by lowering water elevations over a foot during flood events. This setback levee adds 1,600 acres to the floodplain for habitat restoration (GEI).
In the Cosumnes River Preserve an accidental levee breach ended up benefitting all once scientists rediscovered the value of a floodplain riparian ecosystem for both wildlife habitat enhancement and flood prevention. The Cosumnes River drains the Sierra Nevada and enters the lower elevations of the Central Valley of CA. In 1985 a brief levee failure flooded a field and deposited sand and sediment there before the breach was repaired. The field with sediment soon grew into a healthy “accidental” cottonwood, willow and eventually valley oak successional forest (Swenson).
In 1995 an EPA funded study breached a levee on purpose and learned that as water spread out across the greater surface area of the new floodplain the upstream water elevations would be lowered. There was a 50 foot hole created in the levee that added 200 acres into the river’s floodplain. In less than a year the receding floodwaters had deposited sandbars and silt sediments across the field and branch cuttings of willow and cottonwood began to take root (Swenson).
Another levee was breached several times during a severe flooding incident in 2007. Following the flood the U.S. Army Corps of Engineers began a new project upstream of the ’95 breach site and the forest created there by the flooding. They breached and terminated 5.5 miles of levees and along the main levee another breach enabled the floodwaters to enter the 100 acres of floodplain previously inaccessible. A second internal levee was breached and water could enter the forest from the ’95 flood and a small pond for waterfowl. The 5.5 mile section of the levee that was removed was replaced by a low setback levee with underground irrigation pumps. After three years a willow and cottonwood forest had grown on the sand splay and newly deposited sediments on the floodplain. The river saw increasing populations of juvenile chinook salmon and Sacramento splittail that benefitted from the seasonal wetlands’ warm shallow waters and their algal blooms and herbivorous invertebrates who gathered for the algae buffet (Swenson).
The native fish of the Cosumnes River are dependent upon the timing and height of floodwaters during their spawning time of early spring when floodplain waters are colder. Non-native fish spawn later in the spring when the floodplain waters are warmer. By flooding the floodplain during the early spring when most storms occur would benefit the spawning lifestyle of native fish. The preferred depth for Sacramento splittail spawning is 4-6 ft. and for feeding is 1-3 ft. deep while water over six feet can be habitat for larger predators. Floodplain habitat also increases complexity by creating variations in depths, flows and vegetation types to provide a variety of invertebrates with options for different life cycles and species with habitat specific preferences and requirements (Swenson).
The Cosumnes Research Group is studying the ecological benefits of setback levees including the groundwater recharge potential of floodplains. The combined projects added around 300 acres to the most often flooded region and 1,200 acres to the entire floodplain. The deposition of silt and sand sediment with seeds was able to form various terrains and height from elevated sandbars to low wetland ponds within a willow and cottonwood forest including valley oaks on the fringes. The floodplain wetlands are valuable habitat for sandhill cranes and other migratory waterfowl in addition to native fishes including Sacramento splittail and juvenile chinook salmon (Swenson).
Other benefits of setback levees include greatly reduced levee maintenance costs and an increase in the floodplain’s holding capacity that diminishes the flood peak and flow velocity. The floodplain holds water in wetlands for a longer duration and enables downwards percolation into the sand and gravel sediments, recharging groundwater in the process. This recent recharge of groundwater along the Cosumnes River reverses the decline of groundwater levels there since the 1940s. The decades of declining groundwater resulted in low or non-existent flows during the Chinook salmon’s fall spawning season (Swenson).
The multiple breaches along the levees appeared to increase growth of cottonwoods and willows on sand splays that developed directly inside the breach opening. Future growth and sand splay development along breaches would eventually require the formation of new breaches to allow floodwaters to escape the riverbed and form sand splays elsewhere along the levee’s inside border. Water within the floodplain used for early spring spawning warms into the summer and motivates the salmon and springtail to return to the river in order to avoid stranding (Swenson).
The study learned that the location of the levee breach was critical, there needs to be enough space for the floodwaters to enter into the floodplain. If a setback levee is built nearby the breach site, the force of the floodwater may overtop the setback levee. Certain sections of the Cosumnes River have deeply incised channels that prevent the river from connecting with the floodplain (Swenson).
The Cosumnes River study has applications for the Las Vegas Wash also. Though the annual precipitation is less than in the study site, the yearly rainfall from summer thundershowers and winter storms over Las Vegas can be better harnessed if the Las Vegas Wash can spread out during flood events and infiltrate the riparian aquifer beneath the river channel. Currently the Las Vegas Wash is channelized throughout most of its length. The channelization of this desert wash prevents the water from entering the aquifer beneath the riverbed. Further down the length south of the urban core the wash isn’t channelized though a great deal of vegetation grows there from the regular wastewater disposal throughout the year. This is abnormal growth as the wash originally flowed only during storm events and with melting snowfall and not all year long. The regular disposal of wastewater into the Las Vegas Wash allowed certain non-desert vegetation to establish stands along the channel that would ordinarily not be there if desert conditions prevailed. The vegetation along the Las Vegas Wash is more like that found in wetter climates with higher rates of evapotranspiration than from desert vegetation. That results in greater net loss of water from evapotranspiration as it moves down the wash channel and up through the roots of the non-desert vegetation.
Another long term solution for preventing a drought crisis is to maintain and enhance the aquifers of the region. This is like making regular deposits into a personal savings account instead of overspending and then declaring bankruptcy when the account drains out. The yearly floods on the Las Vegas Wash would be the regular deposits to the aquifer bank account once the water is able to infiltrate into the ground following installment of setback levees. Limiting flows on the Las Vegas Wash to correspond with precipitation events only would eliminate the water dependent vegetation and replace this with desert vegetation that does not lose as much water to evapotranspiration. All wastewater should be recycled on site at the wastewater treatment plant and pumped into the aquifer below. In Orange County, CA wastewater recycling was used for years, despite the naysayers crying “toilet to tap”. Recycling wastewater for storage in aquifers would return filtered and clean water below ground into aquifers for additional filtration.
Finally there is the potential for rooftop rainwater harnessing for residential, government and commercial buildings. Not only would rainwater harvesting capture water for storage, it would reduce flash flood damage from the monsoonal thundershowers. By capturing the buildings’ rooftop surface area of floodwater there will be much less runoff from storms rapidly entering the streets. By lowering the amount of storm runoff entering streets the potential for flash flooding is negligible. The rainwater is intercepted by the rooftop collecting device, then filtered and stored below the building in cisterns or storage barrels. Each building alone may seem insignificant though combined and over years of rainwater collection can reduce the take from the Colorado River significantly. Rainwater collecting and filtration is already being used in many other nations such as the Bahamas and India, along with many private residences throughout the Southwestern deserts. There is great potential for Las Vegas to set trends by producing large scale rainwater harvesting systems for the global market. The industrial production of rainwater harvesting kits sold to residences and large scale systems for skyscrapers and commercial or government buildings would provide long term jobs instead of the temporary jobs from a pipeline with a known short shelf life.
If these four methods are implemented in Las Vegas, there will never be any drought scares in the future and no claims made for a short term pipeline from aquifers that will soon be depleted. The combination of transferring floodwater from flood prone Louisiana with the pipeline and mag-lev train, installing setback levees and aquifer infiltration on Las Vegas Wash, recycling wastewater at the source and rooftop rainwater harvesting will end up making Las Vegas true role models in water conservation. Instead of a sequel to the Owens Valley Water Grab filmed on a Nevada set, Las Vegas can star as the positive actor who doesn’t steal water from others and instead can design and build innovative technology for rooftop rainwater harvesting systems, floodwater transfer, setback levees and aquifer infiltration, and wastewater recycling. The people of Las Vegas should consider the SNWA as their tool for future sustainability instead of a propaganda mouthpiece for developers like Wingfield Co. who want urban ratepayers to pick up the tab for a temporary pipeline from aquifers that would only be a greedy developers’ wet dream. The choices people make today will decide if their future holds dreams or nightmares.
The Snake, Delmar, Cave and Spring Valley aquifer system was formed during an ancient climate with increased rates of precipitation. Today steady spring flows from these aquifers depend upon regular recharge from precipitation with minimal discharge as natural spring exit locations and some regulated local withdrawals by humans. Due to the lower rate of precipitation in our current climate the aquifer system is barely able to maintain stable spring flows even under existing conditions with local extractions. Excessive groundwater extractions from the aquifer system that would occur with the proposed SNWA pipeline are well beyond the capability of the spring flow to recover under the present conditions of limited recharge from precipitation.
The proposed SNWA pipeline extractions of billions of gallons per year would lower groundwater levels and drastically reduce spring flow. The decrease in the spring’s water flow would alter the chemistry, temperature and other physical factors that are vital to the survival of the endemic spring snails. The evolution of spring snails from ancient pluvial lakes to small isolated spring streams led them to adapt to the specific conditions of their home spring. The survival of several species of spring snails will be threatened if the spring flow drops as a result of excessive extractions from the SNWA pipeline lowering groundwater levels. The best option for protecting the spring snails and their ecosystem is to list them as endangered under the ESA and then use that classification to protect their sensitive spring habitats including banning any and all out of basin water transfers including yet not limited to the SNWA pipeline.
The spring fed ecosystems provide an oasis habitat for many species in an otherwise harsh desert climate. The spring water enables the growth of algae and periphyton that are then consumed by large numbers of spring snails that cluster around the source. The snails play an important role in spring ecosystems by keeping the algae and periphyton growth in check through constant grazing. Any fluctuations or reductions in spring flow would reduce the spring snail population and result in the unchecked growth of algae and periphyton, creating anoxic conditions of eutrophication.
Spring snails are the base level of primary consumer herbivores that support an entire trophic food web pyramid of secondary consumer predators. The growth of algae and periphyton primary producers are the lowest and widest level of the trophic food web pyramid, the next level above are the spring snail primary consumers and at the top level are secondary consumer predators like trout, eagles and even humans. The reduction in population numbers in ascending levels of the trophic food web pyramid are a result of heat loss from metabolism of consumption. There usually is a tenfold increase in biomass with each descending level of the trophic food pyramid that supports the upper levels. That results in a dependency of top tier predators on large populations of primary consumer spring snails to support a small population of secondary consumers like trout, eagles and humans. There are also no known substitutes for the spring snails that can keep the algae and periphyton growth in check and simultaneously support an entire ecosystem of predators.
The SNWA pipeline is not needed for the survival of the people or economy of Las Vegas and is instead a plan for certain developers to build suburban sprawl communities along the U.S. 93 corridor parallel to the pipeline. One example of the incentive for developers to have the pipeline constructed are the massive campaign contributions from Harvey Whittemore and Albert Seeno’s Wingfield Co. to the campaign of Senator Harry Reid with the understanding that he will look the other way when it comes to Wingfield’s Coyote Springs housing development violating environmental laws. It is clear that the positive financial influence of the Wingfield developers on Senator Reid’s campaign is intended to encourage positive responses from the influential politician when it comes time to secure the water source for their Coyote Springs development via the SNWA pipeline. The Wingfield developers were able to purchase the land where Coyote Springs is located for a low price because it is such a great distance from Las Vegas. However, in this isolated location there is not enough water available for their planned 159,000 homes with seven golf courses and a few casinos without the nearby SNWA pipeline delivering large amounts of water to them. The Wingfield developers are expecting Senator Reid to make loopholes and exceptions to existing environmental laws to allow the SNWA pipeline to be constructed for their benefit as a result of their excessive campaign contributions. The primary motivation for the SNWA pipeline appears to be developers following the Wingfield Company looking to have water rights for suburban sprawl construction on cheap land. This is also evidenced by showing that far more effective and less expensive solutions are available for emergency water storage that are repeatedly ignored by the SNWA officials who appear to be obsessed with their aquifer pipeline plans.
Other options for emergency water storage include widening the floodplain of the Las Vegas Wash by building setback levees, installing rooftop rainwater harvesting systems, recycling wastewater then returning it to local aquifers and also transporting floodwater with a pipeline and an attached mag-lev train from regions like Louisiana that regularly experience severe flooding. Many of these above methods have already been implemented in India, the Bahamas and several U.S. states with great success. There are several additional benefits from floodplain widening with setback levees that include flood prevention, riparian habitat improvement and groundwater recharge. Rooftop rainwater harvesting also shares this extra benefit of flood prevention as it reduces surface area of runoff during summer monsoon thunderstorms. The transfer of floodwater from high precipitation flood prone regions like New Orleans to desert regions like Las Vegas would alleviate flood damage by removing excess water over a short time and using the initial propelling force of the storm surge to power a mag-lev evacuation train. Along the way solar and wind powered pumps can replace the initial momentum of the storm surge pushing the water into the desert. These methods together would prevent any possibility for drought by using the filtered floodwater to recharge local aquifers and for storage in underground cisterns.
The choices we make today as a collective society with regards to water usage and acquisition are critical to the future of many other species and quality of life for humans. If we treat aquifers as disposable as the SNWA pipeline would have us do, we will all suffer the consequences. Our future generations can say goodbye to spring snails, frogs, trout and eagles and say hello to algae choked eutrophic spring streams and eventually a dried up dust bowl while some wealthy and greedy developers profit from their water grab. The question we need to ask ourselves is do we want to subsidize the dreams of developers with the SNWA pipeline or do we want to support our own dreams of a biodiversity in spring stream ecosystems with clean and fresh flowing water?
“Evolution of the Earth” 8th Ed. Donald R. Prothero and Robert H. Dott, Jr. published by McGraw Hill 2010
“Biogeography of Great Basin Aquatic Snails of the Genus Pyrgulopsis” by Robert Hershler and Donald W. Sada; published by Smithsonian Institution (Smithsonian Contribution to Earth Sciences), Washington DC
Center for Biological Diversity; “Petition to List 42 Springsnail Species as Endangered”
“Whittemore Case Lifts Curtain on Political Deals” by David McGrath Schwartz in the Las Vegas Sun on 2/17/ 12
“How Harvey Whittemore Became a Leper” by Jon Ralston in the Las Vegas Sun on 2/15/12
“Whittemore Lawsuits Moving into Stranger than Fiction Territory” by Steve Green in Vegas Inc. on 2/2/12
“Whittemore Wins Water Rights Ruling” by Cy Ryan in the Las Vegas Sun on Thursday, Dec. 4, 2008
“Builder Sees Green Light in Red-flag Economy” by Joe Schoenmann in the Las Vegas Sun on 12/4/08
“The Impending Urban Water Crisis” by Will Doig in Salon.com on 3/31/12
“Political time is right to Change Missouri River Management” by Editorial board on 7/5/11
Saint Louis Today
“Madurai engineers suggest model to harness floodwater” by R. Sivaraman in the Times of India on 9/15/11
San Antonio River Restoration
“Moving Water from Flood to Drought” by Seth Borenstein in the Huffington Post on 09/09/11
“Construction of Yakima River Setback Levee Progresses Well” posted in Dredging Today on 1/13/12
Puyallup River Habitat Mitigation
“Feather River Setback Levee, Designed by GEI Consultants, Recognized as ASCE Sacramento Flood Control” by Jennifer Shelby, CPSM on 2/18/10
Wahkiakum County CFHMP Final Draft
“Nutrient Effects on Spring Flora and Fauna” by Charles A. Jacoby, Thomas K. Frazer and Edward J. Phlips; published by University of Florida
“Springs as Ecosystems” by Robert L. Knight and Sky K. Notestein; published by University of Florida
“Restoring Floods to Floodplains: Riparian and Floodplain Restoration at the Cosumnes River Preserve” by Ramona O. Swenson, Keith Whitener, and Mike Eaton
“Secondary Production, Quantitative Food Webs, and Trophic Position” by Arthur Benke, University of Alabama, 2011
“California Watershed Assessment Manual, Volume II – Chapter 4 Periphyton (Attached Algae and Aquatic Plants) as Indicators of Watershed Condition”
by Fraser Shilling, Sari Sommarstrom, Rick Kattelmann et. al., published by UC Davis,