US lawWashingtonRegulationsTitle 173 — ECOLOGY, DEPARTMENT OFChapter 173-563 — INSTREAM RESOURCES PROTECTION PROGRAM FOR THE MAIN STEM COLUMBIA RIVER IN WASHINGTON STATE173-563-900WAC 173-563-900WAC 173-563-900. Critical flow adjustment—Minimum instantaneous and weekly average flows—Columbia RiverLast amended: 1982Year: 2026Length: 13 wordsOfficial source FIGURE 1 CRITICAL FLOW ADJUSTMENT MINIMUM INSTANTANEOUS AND WEEKLY AVERAGE FLOWS COLUMBIA RIVERPreviousWAC 173-563-100