Print View From: To: Date: Wednesday - September 16, 2009 12:55 PM Subject: Comment on Snake Valley Utah-Nevada Agreement Comment on Snake Valley Utah-Nevada Agreement for aquifer protection; It is difficult for me to directly comment on the Snake Valley Utah-Nevada Agreement as there are many questions unable to be answered as to the potential outcome of this agreement. From a scientific perspective with the goal of protecting ecological integrity of the Snake Valley aquifers, springs and marsh complexes, there is no certain outcome based upon the distribution of allocated and unallocated water. However, it is very clear to me and many others who have begun researching this aquifer complex that ANY excessive withdrawals by either state would spell disaster for the Snake Valley aquifer and related wetlands ecosystem. This comment will focus primarily on the proposal by SNWA to construct a pipeline capable of extracting large amounts of aquifer water to be transported to Las Vegas region. The Snake Valley aquifer complex requires long term protection for the benefit of the ecosystem and also the region's human communities that rely upon this aquifer's water for their survival. Significant risks to the Snake Valley aquifer complex would occur by allowing the SNWA's 300 mile water pipeline to Las Vegas to be constructed. One of the primary risks is from aquifer cavern collapse as the overburden of eroded gravel sediments accumulated above the aquifer will no longer be supported by the water underneath. Aquifer caverns in this region are primarily composed of slightly metamorphosed limestone, and a brief visit to the crumbled rubble of Lehman Cave's Talus Room would show the potential of crumbled aquifers following years of overdraft by the SNWA pipeline. The limestone caverns found at Great Basin National Park's Talus Room were formed and enlarged over the long term wet season years of rainwater percolating downwards and becoming carbonic acid, eating away at the limestone material. According to geological history, the Talus Room's rubble was formed during an interim dry season when the water table dropped several hundreds of meters, resulting in the excessive weight of overburden forcing collapse of the former aquifer's ceiling structure. The ability of the aquifer caverns filled to capacity with water were able to support the overburden's weight under gravity, though loss of the water and replacement with air proved to be insufficient to support such a tremendous burden. It is probable that future drops in the same region's water table due to excessive extractions and transport outside of the region by SNWA's pipeline would result in aquifer caverns becoming empty of water and thus stressed by the gravel overburden's weight, resulting in eventual cavern collapse. According to studies and research on other aquifers, anytime an aquifer is overdrawn and the cavern partially collapses from weight of overburden without water to support the aquifer's ceiling, the result is compaction of sediments and land subsidence visible from the surface. The land subsidence occurs as the empty space of the aquifer cavern is filled with overburden, and the actual elevation of the ground then drops as the overburden fills the empty space of what once was an aquifer. This process has already been documented in several locations, including the permanent loss of the Midwest's Ogallala aquifer, the San Joaquin aquifer's subsidence of nearly twenty feet and sinkholes regularly appearing throughout Florida as their limestone aquifers are overdrawn to the point of ceiling collapse. In every case thus far, once an aquifer is overdrawn to the point of cavern ceiling collapse and surface level land subsidence, there can be no possible returns to the original storage capacity of the aquifer prior to collapse. Another risk of excessive extraction from the SNWA pipeline would be to the ecosystem's food pyramid by preventing natural spring formation at intersections between the water table and above ground openings. Springs in this region occur when the water table is high enough to spill out onto the surface, resulting in unique isolated ecosystems capable of supporting their own endemic biota found nowhere else. The biota found here includes several species of plants, algae and other primary producers that photosynthesize sunlight into energy available for animal consumption. The next level of the food pyramid above the primary producer plants are primary consumers; insects, mollusks and other small organisms that feed directly upon the plants. Above them are secondary consumers; fish, birds and mammals that eat the primary consumers. This entire food pyramid ecosystem is depending upon a regular supply of spring water appearing at this same location every year. One of the focus species of the primary consumer category are spring snails, many considered either threatened and/or endangered because they are unable to travel to other springs and have become their own separate species due to the isolating conditions of the springs located far apart from one another. Each species of spring snail shows physical and physiological traits uniquely evolved in adaptation to their surroundings, usually determined by specific chemical, water and temperature conditions found only in their spring. One example of the genetic isolation found in spring snail species is the Sub-globose Snake Pyrg (Pyrgulopsis saxatilis), found only in Gandy Warm Springs. Other spring snails endemic to the Snake Valley include the Longitudinal Gland Pyrg (Pyrgulopsis anguina) and the Bifid Duct Pyrg (Pyrgulopsis peculiaris). These spring snails have adapted to specific water conditions in the springs where they and their ancestors have lived for thousands of years. This entire ecosystem can become non-existent by a long term drop in the water table resulting from excessive extraction by the SNWA's proposed pipeline. Once the spring snail's habitat becomes unlivable, there is a likely potential that the spring snail will be unable to reproduce and survive the loss of spring water. The outcome of this long term human induced drought would be extinction of each unique species of spring snail with no possible returns. In addition to the spring snails are other secondary consumers that would include the snails at some stage of their life cycle as part of their regular food source. One of these is the least chub (Iotichthys phlegethontis), as mentioned in Appendix 4 of the Utah-Nevada Agreement. Here it states that Snake Valley springs and marshes (Leland Harris Springs, Gandy Marsh and Bishop Springs) play an important role in habitat for the remaining wild populations of the least chub, and without a regular water supply fed by a stable water table the least chub could be extirpated from this crucial habitat. Other threatened fish that depend upon regular surface water supplies from Snake Valley springs include the Bonneville cutthroat trout (Oncorhynchus clarkii utah). Provided that the Snake Valley ecosystem is protected and fish populations are able to increase, these larger native trout species also represent a fisheries resource for humans. Long term protections are needed for the Snake Valley region's springs and their unique ecosystem inhabitants for several reasons. As conscious beings, we humans recognize that water tables can drop from reasons outside our control, such as long term drought and climate change. We also recognize that our actions independent of climactic processes can also result in the drop of the water table, and this is under our control. We can prevent extinctions of the spring snails and all the other animals that depend upon them simply by maintaining the water table to the levels required for the springs to emerge at their surface locations. To maintain the water table levels we only need to be careful monitoring and allocating water from these springs. Current human uses of the Snake Valley aquifer water that would alter the water table levels and spring formation include ranching and limited residential uses. The ranching uses of aquifer water remains in the same region, and eventually percolates downwards and recharges the same aquifer, thus maintaining some neutrality between losses from extractions and gains from recharges to the same water table. However, this would not be the case for the SNWA pipeline, where the aquifer water extracted from the Snake Valley complex would never be recharged to the same location, instead would be lost to the Colorado River system and eventually enter the ocean at the Gulf of California. While this may be good news for the beleaguered and overly saline waters of the Gulf of California, it is certainly a death sentence for the spring snails' food pyramid ecosystems that depend upon Snake Valley aquifer water emerging aboveground at the spring locations. The good news is that with minimal interference the spring snails' food pyramid ecosystem will function normally provided that monitoring of the water table occurs on a regular basis. It would be far more logical and effective to monitor the local ranchers and residential water uses than to further complicate the equation of aquifer extractions and recharge by introducing the SNWA's proposed pipeline capable of extracting far greater quantities with no possible recharge to the original aquifer. Similar to overdrawn then collapsed aquifer caverns and extinction of endemic species, the chance of no possible returns is best avoided. We need to collectively protect the Snake Valley aquifers, springs and all their inhabitants and dependents by preventing the construction of the SNWA's proposed pipeline. In conclusion, by focusing mostly on divisions between allocations the Snake Valley Utah-Nevada Agreement is not adequate to assess the complexity of the aquifer, spring and marsh ecosystems and the diversity of biota that depends upon regular supplies of water. The Snake Valley aquifer complex is not confined to human imposed state boundaries and needs to be treated as a single ecological entity across both sides of the border. Successful conservation of least chub, spring snails, spotted frogs and other endemic inhabitants of the Snake Valley aquifer complex depends upon maintaining the water table at levels required for regular discharge at surface spring flows. A good rule of thumb for a sustainable water distribution agreement would be “Water that comes from Snake Valley stays in Snake Valley.” Since the Snake Valley covers both Utah and Nevada, the distribution of water to residents and ranches can be fairly even across both states. The reason for keeping Snake Valley aquifer’s extracted water allocations in the same original valley basin is to balance the extractions with constant recycling by percolating recharge water back into the same aquifer. This is the same process that Las Vegas implements with Lake Mead’s water; all treated wastewater is recycled back into their original supply at Lake Mead. Geological history reminds us that the full capacity of the Snake Valley aquifer was attained only after thousands of years of rainfall during much wetter climates than our current weather pattern. This indicates that steady exports of aquifer water outside of the original basin (i.e., to Las Vegas and the Colorado River) will result in faster rates of depletion and drawdown of the aquifer than by using and recycling the water for recharge into the original Snake Valley basin. Thank you for your consideration, Mark Miller P.O. Box 1864 Elko, NV 89803