Sedimentation in California Reservoirs: A Long-Term Problem of Immediate Concern

by Ryan J. Mahoney^*

Ryan J. Mahoney

I. INTRODUCTION

Sedimentation in reservoirs is a threat to California’s water supply, water quality, environmental health, and public safety.¹ The accrual of sediments on reservoir floors reduces water storage capacity, causes the heavy concentration of toxic mate-rials, and negatively impacts water supply reliability, reservoir infrastructure, and ecosystems in and around reservoirs.² Despite so many problems arising from sedimentation, sedimentation can be successfully removed, reduced, and eliminated with the adoption of a strong legal framework, strategic prevention and removal plans created using current and reliable data, and sedimentation management plans developed for individual reservoirs based on specific need.³ Water is too important for California to continue to do so little to address reservoir sedimentation.⁴ California’s stability, health, and prosperity are all tied to its water, but the State’s reservoir infrastructure is aging and if nothing is done to address sedimentation the loss of water storage capacity, degradation of water supply reliability, and threats to reservoir infrastructure will continue and grow more severe.⁵