The New Mexico Environment Department (NMED) recently made significant improvements to the accuracy of mapped streams, resulting in better representation - and better protection - of hundreds of additional miles of streams in New Mexico.

The higher-resolution GIS layer, built using National Hydrography Dataset Plus High Resolution data, captures more of the actual stream sinuosity (curves and bends) and extends higher into the watershed to better represent true stream length. With the higher resolution, New Mexico’s assessed stream length increased from 7,832 miles to 8,647 miles.

“Surface water resources are more precious here than most other places in the world,” said NMED Cabinet Secretary James Kenney. “We need the very best scientific data available on our streams to make informed decisions about what is best for New Mexico’s waters.”

"Accurate data on our water resources are essential for scientifically sound decision-making,” said Stacy Timmons, Project Director of the New Mexico Water Data Initiative. “With the new dataset provided on streams in New Mexico, we can build tools that combine these data with other data, such as water quantity and uses, to help inform our watershed management choices." 

Previous versions of the stream dataset had unnatural breaks and unrealistic stream channel configurations. The more refined, high-resolution dataset extends the stream network seamlessly across the terrain to better connect observational data, such as water quality samples or stream flow measurements, with the stream network at a variety of scales (e.g., local, regional and national), which was previously unreliable in many watersheds across the country, but particularly so in the semi-arid watersheds of New Mexico. The higher-resolution dataset improves modeling and analysis, such as pollutant load reductions, flood risk assessments, toxic spill impacts, or invasive species threats, thus supporting better planning and management of our state’s precious water resources.

For a closer look at the improved GIS layer, click here and turn on the “Assessed Waters 2020 DRAFT” layer. The old dataset is available through the “Assessed Waters 2018 IR FINAL” layer. Zoom into your watershed to see what has changed!