The Pollution Control Hearings Board has ruled that the Washington State Department of Ecology has “implied authority” to allow out-of-kind mitigation for impacts to instream flows. The Board’s carefully crafted ruling regarding its own jurisdiction also acknowledges Ecology’s authority to amend numeric instream flow rules and subsequently approve new appropriations without minimum flow conditions.
The Board’s summary judgment ruling in OWL v. KGH rejected arguments by two environmental groups that would have extended last year’s Supreme Court ruling in Swinomish Indian Tribal Community v. Ecology to water rights permitting decisions. Underlying the Board’s decision is its finding that minimum instream flows set by rule are “regulatory” and can be amended, whereas “base flows” are statutory and must be protected from impairment by new water right permits even if regulatory instream flows are made “inapplicable” to a class of water uses.
While concluding that out-of-kind mitigation is not “per se unlawful,” the decision complicates what is expected to become one of Ecology’s principal fixes to water allocation regulatory problems in the post-Swinomish era. What precisely are “base flows” that must be protected from impairment and how do they differ from “minimum flows” set by regulation? How can one establish non-impairment of these base flows on a case-by-case basis, especially if future rule amendments bypass established minimum instream flows that the Supreme Court has described as water rights with priority dates that must be protected from impairment?
 Okanogan Wilderness League (OWL) and Center for Environmental Law and Policy (CELP) v. State of Washington Department of Ecology and Kennewick General Hospital (KGH), PCHB No, 13-146, Order on Motions for Summary Judgment (July 31, 2014).