Sandoval County, NM Environmental Rules: Erosion Control (2026)

Sec. 34-78 requires anyone seeking subdivision plat approval to address terrain management; no plat is approved until the county has reviewed it. Subsection (g), Erosion and drainage plan, requires the subdivider to submit a watershed map showing the entire upper watershed draining into or through the site, including watercourses, topographic conditions, and soil and vegetative types; storm drainage computations for the 100-year frequency storm both entering and leaving the site under pre-development conditions; and post-development runoff calculations comparing flows before and after full build-out. The plan must also show the location, type and size of all proposed drainage and erosion-control structures, and identify drainage easements for floodplains, floodways and watercourses carrying more than 20 cubic feet per second in a 100-year storm.

Subsection (e), Grading plans, requires cross sections and design profiles for every cut and fill, and subsection (h) requires a construction schedule listing start and finish dates for clearing, grubbing and grading, the duration disturbed areas stay exposed, and the stabilization date for those areas. Subsection (f), Landscaping plan, requires revegetation of disturbed areas with a description of stabilization materials and methods. The plan is reviewed alongside the county's soil-suitability requirements in subsection (d), which require lands proposed for subdivision to have soils suited to road fill, foundation support and erosion-control structures, or documented engineering to overcome any limitations, before the county will approve the final plat.