Ann Hayden is a Senior Water Resource Analyst at EDF.

Contrary to the San Diego Union Tribune’s latest editorial on the Delta (“Stop handing Delta water rules to activists”), recent actions to protect imperiled Bay-Delta fish are not simply the result of requests from "environmental activists". Instead, it is the proper enforcement of the state and federal Endangered Species Act that is responsible for these actions taken to protect imperiled Bay-Delta fish. Delta smelt and other pelagic species are at their lowest levels on record; the ESA has been enforced as a last-ditch effort to prevent their extinction.

State and federal fish agencies have years of scientific data to support their determination of the significant role that water operations has played in contributing to the demise of these species. While their recommended actions are largely responsible for keeping key species from extinction, it is unrealistic to expect (as the editorial does) overstressed species to bounce back over night—it will take years of modified operations and additional restoration activities for populations to rebound.

The health of the Bay-Delta estuary and reliability of Delta water supplies are inextricably linked. We at EDF have long believed that until we implement solutions  that can achieve lasting ecological health in the estuary, we will continue to live with the reality that water supplies for Delta-dependent cities and agriculture will remain vulnerable.