Clark County proposes broad stormwater manual changes, including ban on deep injection wells

Clark County officials on Dec. 3, 2025, presented a package of proposed updates to the county's Stormwater Manual and related Title 40 code designed to comply with Department of Ecology Phase I municipal stormwater permit requirements and to improve local stormwater practices.

Consultant Trista Koblowski of OTEC told the Clean Water Commission the update combines three streams of work: seven Ecology‑mandated items (summarized in Appendix 10 of the permit), community‑requested changes, and selected technical updates from the Western Washington Stormwater Manual. "We are responding to that requirement in the latest Phase I permit to update the stormwater and drainage," Koblowski said, noting Ecology will issue formal comments in mid‑December and staff expect a public review period to begin later that month.

Why it matters: county staff said the update is intended to preserve water‑quality protections while clarifying design and maintenance requirements for developers, inspectors and homeowners ahead of an adoption timeline that targets county council action in May–June 2026 and an effective date of July 1, 2026.

Key items outlined by staff include seven permit‑mandated changes—thresholds for redevelopment projects, clarified…