This bill amends existing water law by changing RCW 90.54.020 and RCW 90.03.247. It revises permit and project procedures rather than creating a new criminal offense. Key changes include: limiting authorization of permanent water withdrawals that would conflict with retained base flows to applications approved under RCW 90.03.247; directing the Department of Ecology to evaluate potential new storage projects and their benefits and effects; and declaring that no agency other than the Department of Ecology may establish minimum flows and levels or similar restrictions. The bill also creates specific procedural rules for permits and treatments. When a permit is approved for a stream or water body with adopted minimum flows or levels in effect, the permit must either protect those flows/levels or require water resource mitigation for specified pilot projects under RCW 90.94.090. It allows adjustment of technology-based effluent limits for municipal water treatment plants on the Chehalis, Columbia, Cowlitz, Lewis, or Skagit rivers if the municipality shows its intake is from the same body of water as its discharge and no receiving-water-standard violations or appreciable environmental degradation will result. It authorizes the Department of Ecology to issue a water-right permit for a nonconsumptive hydropower use in a WRIA where adopted minimum instream flows are not being met, or in a water body closed to further appropriation, only if: the diverted water is returned to the same stream reach, installed capacity is under 25 kilowatts, the department determines there would be no net detrimental impact to fish after careful consideration of the Department of Fish and Wildlife’s recommendation, and the department has consulted federally recognized tribes with treaty fishing rights in the WRIA. The bill requires the Department of Ecology, during development of minimum flow proposals, to consult with and carefully consider recommendations from the Department of Fish and Wildlife, Department of Commerce, Department of Agriculture, and representatives of affected Indian tribes. The extracted text does not provide statutory definitions for several terms (for example, “nonconsumptive hydropower use” or “water resource inventory area”), does not fully define each instance of “the department,” and lacks details of the water resource mitigation pilot projects and the parenthetical planning-unit provisions referenced elsewhere.

If enacted, decision-making about minimum stream flows and levels would be centralized with the Department of Ecology, which would now have the exclusive authority to set those limits and would be required to consult with fish and wildlife, commerce, agriculture, and affected tribes when developing proposals. That centralization likely speeds consistency across WRIAs but also concentrates responsibility and political pressure on Ecology; permits for uses of water where minimum flows exist will have to either protect those flows or require approved mitigation for certain pilot projects, and permanent withdrawals that conflict with retained base flows will face stricter approval pathways. Municipalities with treatment plants on the Chehalis, Columbia, Cowlitz, Lewis, or Skagit rivers could see reduced treatment costs or regulatory relief if they can show their intake and discharge are from the same waterbody and no environmental harm results, while small nonconsumptive hydropower developers (under 25 kW) gain a new, limited route to permits so long as water is returned to the same reach, fish impacts are found not to be net detrimental after fish and wildlife review, and tribes are consulted. Practically, Ecology will take on more evaluation work and consultation duties (including new analysis of potential storage projects), which may increase its workload and resource needs; applicants for withdrawals and small hydropower should expect more formal consultation and conditions tied to protecting instream flows. The text omits some implementation details—definitions of key terms and specifics of the referenced mitigation pilot projects—so how mitigation is measured, how storage benefits are scored, and exactly which office in “the department” carries out each duty remain unclear and could affect how readily permits are approved or denied.