A stormwater permit from the Department of Ecology is needed if:
In Yakima County, an excavation and grading plan is required for excavations except as 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 (14.48.100). The plan shall provide for the on-site detention and/or 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.
City of Yakima
In the City of Yakima, an excavation and grading plan is required for excavations except as noted in City of Yakima Code section 11.04.J103.2. Plans, including drainage, are required for public projects in the City of Yakima (15.11.050).
City of Sunnyside
An Erosion and Sedimentation Control Permit (Ord. 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.
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.