The SARP Flow Alteration Assessment provides a regional characterization of the distribution and risk of flow regime impairment of streams and rivers by anthropogenic sources at the NHD+ segment scale. This map illustrates the cumulative risk of flow alteration (RFA) from surface water use by water use sector for Texas and Oklahoma. Â Water use is based on state permits for surface water withdrawals and returns. Â The risk is based on the volume of water used monthly in the drainage area relative to the monthly volume of flow.
RiskÂ of Flow Alteration categories:
Â ZEROÂ Â Â Â Â - 0% mean monthly flow depletion,Â
Â LOWÂ Â Â Â Â Â - > 0-10%,Â
Â MEDIUM - > 10-20%,
Â HIGHÂ Â Â Â Â Â - >20-100%, and
Â PROVISIONAL HIGH â >100%, local review of data is required.
The map is scaled to illustrate larger rivers at the regional scale. Â Zoom in to add small and medium rivers at the state scale and all streams and rivers at the county scale.
The Flow Alteration Assessment was developed in collaboration with regional aquatic ecologists from the South Atlantic and Gulf Coast Prairie LCCs.Â For more information about the risk of flow alteration assessment and how this map was developed for the Southern Instream Flow Network (SIFN), go to the
SIFN Instream Flow Resources web page
Your comments about this map and the databases are welcome. Â Please send comments to the map author using the Comment tab below.
Note: Â Thermopower water use in Texas is reported as Industrial water use.