La Plata County, CO Environmental Rules: Erosion Control (2026)

Section 70-9.IV.C requires the applicant to submit an erosion control plan for the areas affected by the development. It must be detailed enough to evaluate soil erosion and the transport of sediments during construction, and it is drawn at the same scale as the site plan. The plan lists the erosion control measures to be implemented during construction, the scheduling and implementation of those measures, revegetation specifications including seed mix, mulch and application method, the extent of proposed disturbance and revegetation, and detailed drawings of best management practices or references to industry-standard details such as the CDOT M Standard Plans.

The plan is one of four documents, alongside construction plans, grading plans and the drainage report, all prepared under the direction of and signed and sealed by a professional engineer unless the planning engineer waives that. The drainage report itself must cover implementation of the erosion control plan during construction activities. Preliminary versions go in with the project submittal and are revised and resubmitted until approved, and the final signed and sealed set is due before construction. Revisions after approval go to CDD for administrative approval before project completion.

The finish line is written into subsection III.E.1: the applicant must complete improvements, revegetation measures and soil stabilization prior to plat recording or land use permit, and a professional engineer submits a certification that the improvements were built in accordance with the approved plans.

Two companion rules add detail. Section 70-17.III.H requires all disturbed areas to be revegetated or otherwise mitigated to prevent erosion and dust. Section 70-12 requires a Site Revegetation and Weed Control Plan for projects that involve land disturbance, including subdivisions, major land use permits and any development activity that requires a grading permit, and it demands revegetation with appropriate native plant species approved by the county within no more than one calendar year after substantial completion of soil disturbance, phase by phase on phased projects. For extensive disturbance of more than twenty (20) acres, the county can also require long-term monitoring. Agricultural activities such as cleaning and maintaining ditches and canals are exempt from the weed plan. Section 70-9 itself does not apply to development that needs no land-use permit.