In the Fullness of Time

This blog will focus on my fall sabbatical, and the ecology, evolution, and conservation of endangered and rare species in the Death Valley / Owens Valley area of California. Two taxa that I am particularly interested in are the Inyo Mountain salamander, and desert pupfish in the genus Cyprinodon. I plan on exploring not only the science of these species (and others), but also their beauty.

Tuesday, October 26, 2010

Same Planet, Different Worlds

On October 22nd I met with Richard Friese, a US National Park Service hydrologist, to talk about groundwater withdrawals in Nevada, and how they might affect biodiversity in Death Valley. Although the massive project planned for north-central Nevada probably will have little direct effect on Death Valley, other groundwater withdrawals closer to the park’s eastern border do threaten the area’s springs and streams. The Southern Nevada Water Authority (SNWA) holds groundwater rights in several basins with aquifers that drain toward Death Valley, and current withdrawals from the Amargosa Valley, immediately to the east of the park, vastly exceed recharge rates.  Ironically, a “green energy” solar farm planned for the Amargosa Valley will require a substantial amount of groundwater. 
There’s a famous Gary Larson cartoon, “Same Planet, Different World,” a title appropriate for the attitudes of the SNWA and National Park Service on groundwater withdrawals.  It is no surprise that the SNWA is more optimistic about the process than the Park Service. According to Mr. Friese, research suggests that there are “no young waters” in the region’s deep carbonate aquifers.  If most deep groundwater dates from the last glacial maximum, then current recharge rates are low, and pumping will inevitably deplete the aquifers: “Anytime you do large-scale exporting, something is going to dry up.” Another concern is that well monitoring, although important, may give a false sense of security, for hydrogeological models suggest that large groundwater systems may take a millennium to reach a new steady-state. In other words, if monitored wells indicate that storage is declining too rapidly, it could take many years for a decrease in pumping to stabilize the system.  One of the most important lessons from the history of resource exploitation is that a conservative approach, one embracing environmental uncertainty, is necessary if the resource is to be managed in anything approaching a sustainable manner. I would hope that this will be the case with groundwater pumping in the Death Valley region, but I am not optimistic.
The other night, I slept on an alluvial fan at the base of the Avawatz Mountains, just south of Death Valley National Park, near to where Amargosa River pupfish and Saratoga Springs pupfish swim. Eighty miles and several mountain ranges, one 12,000 feet high, stood between my camp and Las Vegas, but a vast, nacreous halo of city lights gleamed above the peaks.   Even though my camp felt lost in the desert’s great emptiness, it was impossible to ignore those lights, or the future that they implied; there are so many people out there, and so much thirst.

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