Mapping Rio Grande Water Rights: A Decision Support Tool for Ecosystem Restoration

The Nature Conservancy of Texas (TNC-Texas) and TNC (TNC-Global) are pursing efforts to identify and acquire water rights that could be dedicated or in other ways managed for the benefit and protection of environmental flows. Due to recent alliances and funding streams, TNC is particularly interested in water rights in the Lower Pecos and Upper Rio Grande watersheds, sub-watersheds of the Rio Grande in Far West Texas.

Before any transactions are made, The Nature Conservancy must determine which water rights they are interested in acquiring. TNC has been working on a water rights mapping platform that allows them to assess how much water is left in the river after the initial diversion, where the return flows go, and if purchased water will reach TNC’s designated priority streams. However, this analysis is limited when water rights are not in the correct location. Thus, this project remedied these inaccuracies in the Lower Pecos and Upper Rio Grande by moving the water right to the correct location.

The resulting products are a static map and web application version that contain the water rights along with other important features like watershed boundaries, water monitoring stations, priority stream segments, and endangered species’ ranges. With water rights in the correct location, it is possible to characterize how water is used in the region and by whom. This report highlights the major water users in each watershed and explains their operations in detail. In addition to who, what, and where of water use, the report emphasizes some of the key legal and third-party considerations TNC should evaluate. The The Nature Conservancy intends to use the map and supporting documentation as a decision support tool for their ecosystem restoration projects.