Liberty Island in the Cache Slough complex of the north Delta appears to provide key habitat for delta smelt and other native fish species. Today, research is being done to examine and learn from the success of the island’s accidental launch into ecosystem restoration—after a levee breach more than a decade ago.
Recent studies have revealed several important observations in the Cache Slough complex:
Groundwater levels in critical agricultural areas worldwide such as India and California’s Central Valley are dropping rapidly. For example, groundwater levels are dropping up to six feet a year in the San Joaquin Valley.
Two technologies that use remote sensing—one airplane-based and one satellite-based—are being used to track groundwater levels worldwide either at the large-scale or at the small-scale. GRACE (Gravity Recovery and Climate Experiment) performs large-scale, long-term analysis using changes in gravity at the earth’s surface to examine the removal of groundwater from large aquifers worldwide.
The Delta Science Program recently convened an independent panel to review the Vernalis Adaptive Management Plan (VAMP) as part of a complete review of San Joaquin River flow objectives by the State Water Resources Control Board (SWRCB).
VAMP is a large-scale, decade-long experimental management program that was designed to protect juvenile Chinook salmon emigrating from the San Joaquin River through the Sacramento-San Joaquin Delta while providing scientific information for the SWRCB’s review and potential modification of the San Joaquin River flow objectives included in the Water Quality Control Plan (Bay-Delta Plan).
VAMP has been conducted annually since 2000 to evaluate the passage and survival of Chinook salmon smolts under a range of combinations of flows in the San Joaquin River and exports by the two major water projects in the Delta (Central Valley Project and State Water Project). When allowed, a physical (rock) barrier at the Head of Old River (HORB) has also been installed as part of the experiment. Several issues have affected VAMP implementation.
What are a California floater and a western pearshell?