Environmental Rules in Washington County, UT (2026)
5 county-level rules, plus city-specific rules for 1 city in Washington County, Utah.
Verified from official government sources
Stormwater Management
Washington County requires every subdivision to install a stormwater drainage system that is separate from the sanitary sewer, with plans stamped by a licensed engineer and approved by the County Public Works Director before construction starts. Ditches and canals cannot carry runoff without the canal company's written consent, and subdivision drainage cannot degrade neighboring property.
Washington County Storm Drainage Plan Rules
Some RestrictionsWashington County Code of Ordinances § 11-5-2
A. Required; Plan Preparation: A stormwater drainage system shall be provided and shall be separate and independent of the sanitary sewage system. The final plans for the drainage system shall be prepared by a licensed engineer and approved by the County Public Works Director prior to any construction taking place. B. Ditches Or Canals: No ditch or canal shall be approved as suitable for the us...
Erosion Control
Any grading or construction on slopes over 20% in unincorporated Washington County needs a hillside development permit, and the drainage plan submitted with it must control erosion and storm runoff throughout construction. The county public works director enforces the standard and can halt work for violations.
Erosion Control on Hillside Grading in Washington County
Some RestrictionsWashington County Code of Ordinances § 10-24-6
15. Necessary measures shall be taken to prevent erosion and scour at all points throughout the development. It shall be mitigated at all points of discharge and at the face of any cut or fill slope throughout the development. 16. During grading or construction on any property, including off site construction, the developer shall control both water used for construction and storm runoff in such...
Flood Zones
Washington County requires a development permit before any construction or fill begins in an area of special flood hazard, based on FEMA's flood insurance rate map dated December 6, 2006. The floodplain administrator reviews plans against flood, erosion and drainage factors before approving work.
Flood Zone Development Permits, Washington County
Some RestrictionsWashington County Code of Ordinances § 12-3-2
The areas of special flood hazard identified by the federal emergency management agency in its flood insurance rate map (FIRM), dated December 6, 2006, and erosion hazard zone delineation study dated May 2007, and any amendments or updates thereto, are hereby adopted by reference and declared to be a part of this title. The FIRM and erosion hazard zone delineation study are on file at the count...
Defensible Space
Inside the Pine Valley Overlay Zone, the county's landscaping standard tells homeowners to clear flammable growth from around their houses: keep twigs, leaves, shrubs, dead grasses, and brush away from the building perimeter. It's framed as encouragement rather than a cited mandate, layered on top of the countywide wildland-urban interface building code.
Pine Valley's Defensible Space Guidance in Washington Co.
Light RestrictionsWashington County Code of Ordinances § 10-29-4.C.2.b
Landscaping: In order to preserve the rural nature of Pine Valley, it is recommended that landscaping incorporates local Utah native plants... It is encouraged to create a defensible space around residential buildings by keeping twigs, leaves, shrubs, dead grasses and brush away from the perimeter of the structures. Washington County Community Fire Planning recognizes that many communities are ...
Flood Elevation Requirements
Washington County requires new and substantially improved residential structures in a mapped flood hazard area to elevate the lowest floor at least two feet above the base flood elevation, with a registered engineer or architect certifying the design.
Base Flood Elevation Freeboard, Washington County
Some RestrictionsWashington County Code of Ordinances § 12-5-2(A)
Residential Construction: New construction and substantial improvement of any residential structure shall have the lowest floor (including basement) elevated a minimum of two feet (2') above the base flood elevation and be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting the...
Environmental Rules by City in Washington County
1 cities in Washington County have their own environmental rules rules. Each link goes to that city's dedicated page with code citations.
All Washington County ordinances
See every category we cover for Washington County: parking, noise, fences, fires, animals, pools, and more.
Washington County Ordinance Hub →