{
  "claims": [
    {
      "claim": {
        "claim_id": "claim-del-valle-boat-inspection",
        "evidence_ids": [
          "evidence-del-valle-boat-inspection",
          "evidence-del-valle-ebrpd-boat-inspection",
          "evidence-ebrpd-mussels-del-valle-inspection"
        ],
        "predicate": "boat_inspection_required",
        "spatial_scope_ids": [
          "scope-lake-del-valle"
        ],
        "subject_id": "lake-del-valle",
        "temporal_scope": null,
        "value": true
      },
      "evidence": [
        {
          "claim_id": "claim-del-valle-boat-inspection",
          "evidence_id": "evidence-del-valle-boat-inspection",
          "notes": "",
          "observation_id": "observation-del-valle-boating-swimming",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-boat-inspection",
          "evidence_id": "evidence-del-valle-ebrpd-boat-inspection",
          "notes": "",
          "observation_id": "observation-del-valle-ebrpd-golden-mussel",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-boat-inspection",
          "evidence_id": "evidence-ebrpd-mussels-del-valle-inspection",
          "notes": "",
          "observation_id": "observation-ebrpd-mussels-program-scope",
          "stance": "supports"
        }
      ],
      "observations": [
        {
          "artifact_refs": [],
          "content": "The page lists two swimming beaches, lifeguards during posted periods, boat rentals, and a public launch for boats of any size; it warns that boaters must comply with the Invasive Mussel Prevention Program and mandatory inspections.",
          "observation_id": "observation-del-valle-boating-swimming",
          "observed_at": null,
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-reserveamerica-del-valle-overview-110003"
        },
        {
          "artifact_refs": [],
          "content": "At retrieval, the page stated that a boat launched at Contra Loma would be quarantined for 30 days from inspected lakes including Del Valle; vessels must be cleaned, drained, and dried, and boat bands are honored only by the lake that issued them. It also requires campground guests with watercraft to complete inspection before campground check-in.",
          "observation_id": "observation-del-valle-ebrpd-golden-mussel",
          "observed_at": "2026-09-20T00:00:00+00:00",
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-ebrpd-del-valle-park-page"
        },
        {
          "artifact_refs": [],
          "content": "EBRPD requires watercraft inspection at Contra Loma, Del Valle, Lake Chabot, Quarry Lakes, and Shadow Cliffs. Covered craft include boats, kayaks, canoes, sailboats, inflatable craft, and every form of floating board. Campers with watercraft must complete inspection before campground check-in.",
          "observation_id": "observation-ebrpd-mussels-program-scope",
          "observed_at": null,
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-ebrpd-invasive-mussel-program"
        }
      ],
      "sources": [
        {
          "locator": "https://www.reserveamerica.com/explore/del-valle/EB/110003/overview",
          "publisher": "ReserveAmerica / East Bay Regional Park District",
          "source_id": "source-reserveamerica-del-valle-overview-110003"
        },
        {
          "locator": "https://www.ebparks.org/parks/del-valle",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-del-valle-park-page"
        },
        {
          "locator": "https://www.ebparks.org/recreation/boating/invasive-mussels",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-invasive-mussel-program"
        }
      ]
    },
    {
      "claim": {
        "claim_id": "claim-del-valle-ebrpd-clean-drain-dry",
        "evidence_ids": [
          "evidence-del-valle-ebrpd-clean-drain-dry",
          "evidence-ebrpd-mussels-clean-drain-dry"
        ],
        "predicate": "watercraft_preparation",
        "spatial_scope_ids": [
          "scope-lake-del-valle"
        ],
        "subject_id": "lake-del-valle",
        "temporal_scope": {
          "ends_on": "2026-09-20",
          "starts_on": "2026-09-20"
        },
        "value": [
          "clean",
          "drain",
          "dry"
        ]
      },
      "evidence": [
        {
          "claim_id": "claim-del-valle-ebrpd-clean-drain-dry",
          "evidence_id": "evidence-del-valle-ebrpd-clean-drain-dry",
          "notes": "",
          "observation_id": "observation-del-valle-ebrpd-golden-mussel",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-clean-drain-dry",
          "evidence_id": "evidence-ebrpd-mussels-clean-drain-dry",
          "notes": "",
          "observation_id": "observation-ebrpd-mussels-contra-loma",
          "stance": "supports"
        }
      ],
      "observations": [
        {
          "artifact_refs": [],
          "content": "At retrieval, the page stated that a boat launched at Contra Loma would be quarantined for 30 days from inspected lakes including Del Valle; vessels must be cleaned, drained, and dried, and boat bands are honored only by the lake that issued them. It also requires campground guests with watercraft to complete inspection before campground check-in.",
          "observation_id": "observation-del-valle-ebrpd-golden-mussel",
          "observed_at": "2026-09-20T00:00:00+00:00",
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-ebrpd-del-valle-park-page"
        },
        {
          "artifact_refs": [],
          "content": "The current notice reports golden mussels at Contra Loma and states that a boat launched there is quarantined for 30 days from inspected lakes including Del Valle. All vessels should be cleaned, drained, and dried, and bands are honored only at their issuing lake.",
          "observation_id": "observation-ebrpd-mussels-contra-loma",
          "observed_at": "2026-09-20T00:00:00+00:00",
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-ebrpd-invasive-mussel-program"
        }
      ],
      "sources": [
        {
          "locator": "https://www.ebparks.org/parks/del-valle",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-del-valle-park-page"
        },
        {
          "locator": "https://www.ebparks.org/recreation/boating/invasive-mussels",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-invasive-mussel-program"
        }
      ]
    },
    {
      "claim": {
        "claim_id": "claim-del-valle-ebrpd-contra-loma-quarantine",
        "evidence_ids": [
          "evidence-del-valle-ebrpd-contra-loma-quarantine",
          "evidence-ebrpd-mussels-contra-loma-quarantine"
        ],
        "predicate": "cross_lake_boat_quarantine",
        "spatial_scope_ids": [
          "scope-lake-del-valle"
        ],
        "subject_id": "lake-del-valle",
        "temporal_scope": {
          "ends_on": "2026-09-20",
          "starts_on": "2026-09-20"
        },
        "value": {
          "duration_days": 30,
          "restricted_destination": "Lake Del Valle",
          "trigger_lake": "Contra Loma Reservoir"
        }
      },
      "evidence": [
        {
          "claim_id": "claim-del-valle-ebrpd-contra-loma-quarantine",
          "evidence_id": "evidence-del-valle-ebrpd-contra-loma-quarantine",
          "notes": "",
          "observation_id": "observation-del-valle-ebrpd-golden-mussel",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-contra-loma-quarantine",
          "evidence_id": "evidence-ebrpd-mussels-contra-loma-quarantine",
          "notes": "",
          "observation_id": "observation-ebrpd-mussels-contra-loma",
          "stance": "supports"
        }
      ],
      "observations": [
        {
          "artifact_refs": [],
          "content": "At retrieval, the page stated that a boat launched at Contra Loma would be quarantined for 30 days from inspected lakes including Del Valle; vessels must be cleaned, drained, and dried, and boat bands are honored only by the lake that issued them. It also requires campground guests with watercraft to complete inspection before campground check-in.",
          "observation_id": "observation-del-valle-ebrpd-golden-mussel",
          "observed_at": "2026-09-20T00:00:00+00:00",
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-ebrpd-del-valle-park-page"
        },
        {
          "artifact_refs": [],
          "content": "The current notice reports golden mussels at Contra Loma and states that a boat launched there is quarantined for 30 days from inspected lakes including Del Valle. All vessels should be cleaned, drained, and dried, and bands are honored only at their issuing lake.",
          "observation_id": "observation-ebrpd-mussels-contra-loma",
          "observed_at": "2026-09-20T00:00:00+00:00",
          "observer": "user-supplied page transcription",
          "retrieved_at": "2026-09-20T00:00:00+00:00",
          "source_id": "source-ebrpd-invasive-mussel-program"
        }
      ],
      "sources": [
        {
          "locator": "https://www.ebparks.org/parks/del-valle",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-del-valle-park-page"
        },
        {
          "locator": "https://www.ebparks.org/recreation/boating/invasive-mussels",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-invasive-mussel-program"
        }
      ]
    }
  ],
  "entities": [
    {
      "entity_id": "lake-del-valle",
      "kind": "lake",
      "name": "Lake Del Valle"
    }
  ],
  "history": [
    {
      "action": "ADD",
      "change_set_id": "wp-20260920-del-valle-ebrpd-park-page",
      "evidence_refs": [],
      "knowledge_gap_refs": [],
      "path": "canonical/v0/observations/observation-del-valle-ebrpd-golden-mussel.json",
      "reason": "Add EBRPD park-page evidence, preserve conflicts, and refine current Del Valle knowledge.",
      "record_id": "observation-del-valle-ebrpd-golden-mussel",
      "record_type": "observation",
      "summary": "Add EBRPD Del Valle park-page evidence, corroborate the 150-site campground inventory, preserve the acreage conflict, and capture dated operational conditions and rechecks."
    }
  ],
  "navigation": {
    "next_id": "observation-del-valle-ebrpd-hours",
    "position": 20,
    "previous_id": "observation-del-valle-ebrpd-fees",
    "total": 1318
  },
  "observations": [
    {
      "artifact_refs": [],
      "content": "At retrieval, the page stated that a boat launched at Contra Loma would be quarantined for 30 days from inspected lakes including Del Valle; vessels must be cleaned, drained, and dried, and boat bands are honored only by the lake that issued them. It also requires campground guests with watercraft to complete inspection before campground check-in.",
      "observation_id": "observation-del-valle-ebrpd-golden-mussel",
      "observed_at": "2026-09-20T00:00:00+00:00",
      "observer": "user-supplied page transcription",
      "retrieved_at": "2026-09-20T00:00:00+00:00",
      "source_id": "source-ebrpd-del-valle-park-page"
    }
  ],
  "record": {
    "artifact_refs": [],
    "content": "At retrieval, the page stated that a boat launched at Contra Loma would be quarantined for 30 days from inspected lakes including Del Valle; vessels must be cleaned, drained, and dried, and boat bands are honored only by the lake that issued them. It also requires campground guests with watercraft to complete inspection before campground check-in.",
    "observation_id": "observation-del-valle-ebrpd-golden-mussel",
    "observed_at": "2026-09-20T00:00:00+00:00",
    "observer": "user-supplied page transcription",
    "retrieved_at": "2026-09-20T00:00:00+00:00",
    "source_id": "source-ebrpd-del-valle-park-page"
  },
  "record_type": "observation",
  "related_records": [],
  "sources": [
    {
      "locator": "https://www.ebparks.org/parks/del-valle",
      "publisher": "East Bay Regional Park District",
      "source_id": "source-ebrpd-del-valle-park-page"
    }
  ]
}