Permits & Regulations

Stormwater Permits & Regulations


A stormwater permit from the Department of Ecology is needed if:
  • A construction project will disturb 1 or more acres on a site, or, 1 or more acres will be disturbed as part of a larger plan, AND, if stormwater runoff can leave the site.
  • An industrial facility has a specific Standard Industrial Code (SIC) and if there is a discharge to surface water or MS4 .
  • A sand and gravel facility with a specific SIC discharges process water, stormwater, and mine dewatering water associated with sand and gravel operations, rock quarries and similar mining activities, including stockpiles of mined materials, concrete batch operations, and hot mix asphalt operations.

Yakima County


In Yakima County, an excavation and grading plan is required for excavations. Exceptions are noted in Yakima County Code section 13.05.160. A site drainage plan is required to provide adequate drainage for short or long subdivisions in the County. The plan provides for the on-site retention of the total water intercepted and collected by the development for the 10-year design storm. All runoff from commercial and private road approaches must be contained on site (10.08.070) as well.

The Yakima County ordinance to include construction and post-construction requirements was amended in 2010.

2018 NPDES Permit Submission Documents:
  1. Annual Report for Yakima County
  2. Yakima County Internal Coordination Mechanisms

City of Selah


Municode Chapter 9.22 covers Illicit connections and discharges to the municipal separate storm sewer system.

2018 NPDES Permit Submission Documents:
  1. Annual Report for City of Selah
  2. City of Selah Internal Coordination Mechanisms

City of Sunnyside


An Erosion and Sedimentation Control Permit (Ordinance 1630, 1988) is required “to grub, clear, grade, fill, excavate, quarry, mine and/or stockpile soil on any property” within the City of Sunnyside or to improve or develop any property there.

2018 NPDES Permit Submission Documents:
  1. Annual Report for City of Sunnyside
  2. City of Sunnyside Internal Coordination Mechanisms

City of Union Gap


A drainage plan is required for subdivisions in the City of Union Gap 17.11.020. Grading and drainage information is required for all permit categories as described in Union Gap City Code section 9.34.070.

An ordinance requiring construction and post-construction best management practices (BMPs) must be adopted by the regional co-permittees no later than February 16, 2010.

2018 NPDES Permit Submission Documents:
  1. Annual Report for City of Union Gap