Human Transformation of California: Botany, History, and Sociology
Manning, Sara .
Environmental effects of water export from Owens Valley.
OWENS Valley is the source of a major, century-old interbasin water transfer. The human history of Los Angeles’s land and water “grab” in Owens Valley has been well documented, but the ecological consequences of the hydrologic alterations—which continue today—are less well known. From 1913–1970, much of the water exported from the valley was surface flow, but when aqueduct capacity was enlarged in 1970, exports were augmented with large volumes of pumped groundwater. Pumping threatens groundwater-dependent alkali meadow, which dominates the valley floor. Extensive alkali meadow is uncommon throughout the rest of California and the Great Basin. In Owens Valley, it is dominated by perennial, native grasses, harbors rare plant and animal species, and persists due to a shallow water table maintained by annual snowmelt runoff from the Sierra Nevada. For many years, I have monitored the effects of groundwater pumping on Owens Valley alkali meadow. Field and remotely sensed measurements show a correlation between changes in meadow plant cover and depth to the water table. Data also reveal that groundwater pumping promotes changes in dominant species, and conversion from meadow to scrub. Data suggest that prolonged pumping-induced drawdowns beneath meadows could result in the demise of native vegetation, an increase in blowing dust, and the loss of a rare California habitat. If these results were used to amend local groundwater pumping practices, lessons learned could assist in achieving sustainable water development in Owens Valley and other parts of the west. -DU
Log in to add this item to your schedule
Inyo County Water Department
1 - Inyo County Water Department, 163 May St., Bishop, California, 93514, USA
Presentation Type: Symposium or Colloquium Presentation
Date: Tuesday, August 1st, 2006
Time: 2:15 PM