Document Details

Beneath the Surface: Why Reservoirs Won’t Solve California’s Water Woes

Sofia Prado-Irwin, Aruna Prabhala, John Buse, Tiffany Yap, Frances Tinney | November 19th, 2024


Water storage and conveyance have fundamentally shaped modern California. The vast agricultural industry, as well as globally important cities like Los Angeles, were made possible by storing and moving water around the state. Reservoirs are one of the primary components of California’s water storage system. There are nearly 1,500 surface storage reservoirs throughout the state, which together can store a year’s supply of water for farms and cities.

But reservoirs come with high costs. They destroy and degrade habitats and alter flows in rivers and streams, harming native fish and wildlife. They emit significant amounts of greenhouse gases, worsening climate change. They cost taxpayers billions of dollars to build and maintain. And as the climate continues to warm, reservoirs will become less efficient, losing more and more of the water they hold to evaporation. 

This report examines reservoirs’ environmental harms and explains why new reservoirs are not the solution to our 21st century water problems. 

Keywords

ecosystem management, flows, storage, water supply