Assessment Executive Summary: In the past decade there has been increased interest in providing water to meet the needs of riparian and aquatic ecosystems in the western United States and policymakers are using their knowledge of environmental flow needs to advocate for both political and scientific changes. However, there are significant challenges associated with including environmental flows in water management and planning. First, water rights for environmental flows are not universal, and in many cases legal tools used to incorporate the environment into water management and planning only require new users to consider their impact to water in the environment. Second, it can be difficult to include the needs of riparian and aquatic ecosystems in new plans when other existing uses already outstrip supplies.
While the science of environmental flows is ever-growing and expanding, there are few compendiums of efforts to define the quantity of water needed to maintain riparian and aquatic species. This Assessment Report, funded by the Desert Landscape Conservation Cooperative (LCC), synthesizes data from the Desert Flows Database, a geospatial tool that combines data from 408 articles or reports on environmental flows from across the desert watersheds of the United States and Mexico. The goal of this report is to summarize what we know (and do not know) about flow needs and responses and identify critical data gaps in flow need and flow response information.
