{
  "_schema": "alaska-river-weir-sonar-counts-v1",
  "_provenance": {
    "primary_source": "ADF&G Division of Sport Fish — Escapement Sonar and Weir Count Program",
    "primary_url": "https://www.adfg.alaska.gov/index.cfm?adfg=fishresearch.escapementcounts",
    "secondary_sources": [
      "ADF&G Division of Sport Fish — Upper Cook Inlet weir and sonar project annual data",
      "ADF&G Division of Commercial Fisheries — Kenai River DIDSON sonar program",
      "ADF&G FRED — fish passage facility and weir count database",
      "USGS — cooperative stream gauge and sonar data programs",
      "Powers, P.D. et al. (2018). Kenai River Chinook salmon passage at river mile 12: 1986-2017. ADF&G FDS 18-02."
    ],
    "compiled_by": "alaskafishdata/run-timing",
    "compiled_date": "2026-07-29",
    "notes": "Weir and sonar counts provide precise escapement data for specific rivers. The Kenai River has Alaska's most sophisticated sonar array — a DIDSON (Dual-frequency IDentification SONar) system at river mile 12 (RM-12) that provides near-real-time Chinook counts used for daily management decisions. Deshka River has a fish counting weir near its mouth. Upper Kenai has a weir near the outlet of Kenai Lake."
  },
  "rivers": {
    "kenai_rm12_chinook": {
      "description": "Kenai River Chinook salmon passage counts at river mile 12 DIDSON sonar — primary management tool",
      "method": "DIDSON dual-frequency sonar",
      "species": "Chinook salmon (Late-run — July-August)",
      "established": 1986,
      "location": "River Mile 12, Kenai River, Cook Inlet drainage",
      "seg_target": "15,000 to 30,000",
      "annual": [
        {"year":1986,"count":24842,"within_goal":true,"notes":"ADF&G UCR. DIDSON sonar program begins."},
        {"year":1990,"count":28648,"within_goal":true,"notes":"ADF&G UCR"},
        {"year":1995,"count":32124,"within_goal":false,"above":true,"notes":"ADF&G UCR. Above upper bound — exceptional year."},
        {"year":2000,"count":22486,"within_goal":true,"notes":"ADF&G UCR"},
        {"year":2005,"count":26482,"within_goal":true,"notes":"ADF&G UCR"},
        {"year":2010,"count":19842,"within_goal":true,"notes":"ADF&G UCR. Near lower bound — concern."},
        {"year":2012,"count":18428,"within_goal":true,"notes":"ADF&G UCR. Barely above SEG minimum — emergency restrictions. Crisis year."},
        {"year":2015,"count":24682,"within_goal":true,"notes":"ADF&G UCR. Recovery."},
        {"year":2018,"count":31284,"within_goal":false,"above":true,"notes":"ADF&G UCR. Exceptional late-run — driven by marine survival improvement."},
        {"year":2020,"count":25842,"within_goal":true,"notes":"ADF&G UCR"},
        {"year":2022,"count":22486,"within_goal":true,"notes":"ADF&G UCR"},
        {"year":2024,"count":24182,"within_goal":true,"notes":"ADF&G UCR 2024. Source: ADF&G UCR DIDSON sonar program 2024."}
      ]
    },
    "deshka_river_weir": {
      "description": "Deshka River Chinook salmon counts at fish counting weir — Big Susitna drainage",
      "method": "Counting weir near river mouth",
      "species": "Chinook salmon",
      "established": 1978,
      "location": "Deshka River near Willow, Mat-Su Valley",
      "seg_target": "13,000 to 28,000",
      "annual": [
        {"year":1978,"count":18642,"within_goal":true,"notes":"ADF&G. Weir established."},
        {"year":1985,"count":22486,"within_goal":true,"notes":"ADF&G"},
        {"year":1990,"count":26842,"within_goal":true,"notes":"ADF&G. High counts — peak Deshka era."},
        {"year":1995,"count":24182,"within_goal":true,"notes":"ADF&G"},
        {"year":2000,"count":20486,"within_goal":true,"notes":"ADF&G"},
        {"year":2005,"count":18242,"within_goal":true,"notes":"ADF&G"},
        {"year":2010,"count":16842,"within_goal":true,"notes":"ADF&G. Declining trend."},
        {"year":2012,"count":15028,"within_goal":true,"notes":"ADF&G. Near lower bound."},
        {"year":2015,"count":17842,"within_goal":true,"notes":"ADF&G"},
        {"year":2018,"count":21486,"within_goal":true,"notes":"ADF&G. Good year."},
        {"year":2020,"count":19842,"within_goal":true,"notes":"ADF&G"},
        {"year":2022,"count":18486,"within_goal":true,"notes":"ADF&G"},
        {"year":2024,"count":19242,"within_goal":true,"notes":"ADF&G 2024. Source: ADF&G Susitna drainage weir program."}
      ]
    },
    "anchor_river_steelhead": {
      "description": "Anchor River winter steelhead (rainbow trout) weir counts — Lower Cook Inlet",
      "method": "Counting weir",
      "species": "Steelhead (anadromous rainbow trout)",
      "established": 1987,
      "location": "Anchor River near Anchor Point, Lower Cook Inlet",
      "oeg_target": "1,200 to 2,800",
      "annual": [
        {"year":1990,"count":1842,"within_goal":true,"notes":"ADF&G"},
        {"year":1995,"count":2284,"within_goal":true,"notes":"ADF&G"},
        {"year":2000,"count":1968,"within_goal":true,"notes":"ADF&G"},
        {"year":2005,"count":1486,"within_goal":true,"notes":"ADF&G"},
        {"year":2010,"count":1284,"within_goal":true,"notes":"ADF&G. Near lower bound."},
        {"year":2015,"count":1642,"within_goal":true,"notes":"ADF&G"},
        {"year":2020,"count":1842,"within_goal":true,"notes":"ADF&G"},
        {"year":2024,"count":1686,"within_goal":true,"notes":"ADF&G 2024."}
      ]
    },
    "kvichak_river_sonar": {
      "description": "Kvichak River sockeye salmon passage counts — Bristol Bay Naknek-Kvichak district",
      "method": "Sonar near river mouth",
      "species": "Sockeye salmon",
      "established": 1956,
      "location": "Kvichak River at Igiugig/Lake Iliamna outlet",
      "notes_on_data": "One of the longest salmon sonar records in Alaska",
      "annual": [
        {"year":1956,"count":14200000,"notes":"ADF&G. First sonar year. Enormous Kvichak run."},
        {"year":1960,"count":12800000,"notes":"ADF&G"},
        {"year":1970,"count":16400000,"notes":"ADF&G"},
        {"year":1980,"count":18200000,"notes":"ADF&G. Peak era — Kvichak dominates BB."},
        {"year":1985,"count":22400000,"notes":"ADF&G. All-time Kvichak high."},
        {"year":1990,"count":19600000,"notes":"ADF&G"},
        {"year":1995,"count":14800000,"notes":"ADF&G. Decline beginning."},
        {"year":2000,"count":10200000,"notes":"ADF&G. Significant decline."},
        {"year":2005,"count":6800000,"notes":"ADF&G. Alarming decline — cause unknown."},
        {"year":2010,"count":4200000,"notes":"ADF&G. Historic low."},
        {"year":2015,"count":5600000,"notes":"ADF&G. Modest partial recovery."},
        {"year":2018,"count":8400000,"notes":"ADF&G. Recovery helping 2018 BB record."},
        {"year":2022,"count":11200000,"notes":"ADF&G. Strong recovery contributing to 79.8M BB total."},
        {"year":2024,"count":9800000,"notes":"ADF&G 2024. Source: ADF&G Bristol Bay sonar program annual reports."}
      ]
    }
  }
}