{
  "claims": [
    {
      "claim": {
        "claim_id": "claim-del-valle-ebrpd-east-beach-algae",
        "evidence_ids": [
          "evidence-del-valle-ebrpd-east-beach-algae",
          "evidence-ebrpd-algae-east-beach-caution",
          "evidence-ebrpd-swimming-east-caution",
          "evidence-ebrpd-water-quality-east-caution"
        ],
        "predicate": "water_quality_advisory",
        "spatial_scope_ids": [
          "scope-del-valle-east-beach"
        ],
        "subject_id": "beach-del-valle-east",
        "temporal_scope": {
          "ends_on": "2026-09-20",
          "starts_on": "2026-09-20"
        },
        "value": "caution"
      },
      "evidence": [
        {
          "claim_id": "claim-del-valle-ebrpd-east-beach-algae",
          "evidence_id": "evidence-del-valle-ebrpd-east-beach-algae",
          "notes": "",
          "observation_id": "observation-del-valle-ebrpd-water-quality",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-east-beach-algae",
          "evidence_id": "evidence-ebrpd-algae-east-beach-caution",
          "notes": "",
          "observation_id": "observation-ebrpd-algae-current-del-valle",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-east-beach-algae",
          "evidence_id": "evidence-ebrpd-swimming-east-caution",
          "notes": "",
          "observation_id": "observation-ebrpd-swimming-current-beaches",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-east-beach-algae",
          "evidence_id": "evidence-ebrpd-water-quality-east-caution",
          "notes": "",
          "observation_id": "observation-ebrpd-water-quality-current-del-valle",
          "stance": "supports"
        }
      ],
      "observations": [
        {
          "artifact_refs": [],
          "content": "At retrieval, the EBRPD page posted a blue-green algae Caution Advisory for the East Swim Beach and stated that the West Swim Beach had no water because of low lake levels.",
          "observation_id": "observation-del-valle-ebrpd-water-quality",
          "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": "At retrieval, the current-conditions table listed a Caution Advisory for the Del Valle East Swim Beach and no advisory for the West Swim Beach, where it reported no water because of low lake levels.",
          "observation_id": "observation-ebrpd-algae-current-del-valle",
          "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-blue-green-algae"
        },
        {
          "artifact_refs": [],
          "content": "At retrieval, East Beach had a blue-green algae Caution Advisory and West Beach had no water because of low lake levels.",
          "observation_id": "observation-ebrpd-swimming-current-beaches",
          "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-swimming"
        },
        {
          "artifact_refs": [],
          "content": "At retrieval, the table listed a Caution algae advisory at Del Valle East Beach and no advisory at West Beach, where there was no water because of low lake levels.",
          "observation_id": "observation-ebrpd-water-quality-current-del-valle",
          "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-current-water-quality"
        }
      ],
      "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/natural-resources/water-quality/blue-green-algae",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-blue-green-algae"
        },
        {
          "locator": "https://www.ebparks.org/recreation/swimming/del-valle",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-del-valle-swimming"
        },
        {
          "locator": "https://www.ebparks.org/natural-resources/water-quality",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-current-water-quality"
        }
      ]
    },
    {
      "claim": {
        "claim_id": "claim-del-valle-ebrpd-west-beach-water",
        "evidence_ids": [
          "evidence-del-valle-ebrpd-west-beach-water",
          "evidence-ebrpd-algae-west-beach-no-water",
          "evidence-ebrpd-swimming-west-no-water",
          "evidence-ebrpd-water-quality-west-no-water"
        ],
        "predicate": "water_availability",
        "spatial_scope_ids": [
          "scope-del-valle-west-beach"
        ],
        "subject_id": "beach-del-valle-west",
        "temporal_scope": {
          "ends_on": "2026-09-20",
          "starts_on": "2026-09-20"
        },
        "value": "no_water"
      },
      "evidence": [
        {
          "claim_id": "claim-del-valle-ebrpd-west-beach-water",
          "evidence_id": "evidence-del-valle-ebrpd-west-beach-water",
          "notes": "",
          "observation_id": "observation-del-valle-ebrpd-water-quality",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-west-beach-water",
          "evidence_id": "evidence-ebrpd-algae-west-beach-no-water",
          "notes": "",
          "observation_id": "observation-ebrpd-algae-current-del-valle",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-west-beach-water",
          "evidence_id": "evidence-ebrpd-swimming-west-no-water",
          "notes": "",
          "observation_id": "observation-ebrpd-swimming-current-beaches",
          "stance": "supports"
        },
        {
          "claim_id": "claim-del-valle-ebrpd-west-beach-water",
          "evidence_id": "evidence-ebrpd-water-quality-west-no-water",
          "notes": "",
          "observation_id": "observation-ebrpd-water-quality-current-del-valle",
          "stance": "supports"
        }
      ],
      "observations": [
        {
          "artifact_refs": [],
          "content": "At retrieval, the EBRPD page posted a blue-green algae Caution Advisory for the East Swim Beach and stated that the West Swim Beach had no water because of low lake levels.",
          "observation_id": "observation-del-valle-ebrpd-water-quality",
          "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": "At retrieval, the current-conditions table listed a Caution Advisory for the Del Valle East Swim Beach and no advisory for the West Swim Beach, where it reported no water because of low lake levels.",
          "observation_id": "observation-ebrpd-algae-current-del-valle",
          "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-blue-green-algae"
        },
        {
          "artifact_refs": [],
          "content": "At retrieval, East Beach had a blue-green algae Caution Advisory and West Beach had no water because of low lake levels.",
          "observation_id": "observation-ebrpd-swimming-current-beaches",
          "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-swimming"
        },
        {
          "artifact_refs": [],
          "content": "At retrieval, the table listed a Caution algae advisory at Del Valle East Beach and no advisory at West Beach, where there was no water because of low lake levels.",
          "observation_id": "observation-ebrpd-water-quality-current-del-valle",
          "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-current-water-quality"
        }
      ],
      "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/natural-resources/water-quality/blue-green-algae",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-blue-green-algae"
        },
        {
          "locator": "https://www.ebparks.org/recreation/swimming/del-valle",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-del-valle-swimming"
        },
        {
          "locator": "https://www.ebparks.org/natural-resources/water-quality",
          "publisher": "East Bay Regional Park District",
          "source_id": "source-ebrpd-current-water-quality"
        }
      ]
    }
  ],
  "entities": [
    {
      "entity_id": "beach-del-valle-east",
      "kind": "swim_beach",
      "name": "Del Valle East Swim Beach"
    },
    {
      "entity_id": "beach-del-valle-west",
      "kind": "swim_beach",
      "name": "Del Valle West Swim Beach"
    }
  ],
  "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-water-quality.json",
      "reason": "Add EBRPD park-page evidence, preserve conflicts, and refine current Del Valle knowledge.",
      "record_id": "observation-del-valle-ebrpd-water-quality",
      "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-family-booking",
    "position": 24,
    "previous_id": "observation-del-valle-ebrpd-seasonal-stores",
    "total": 1318
  },
  "observations": [
    {
      "artifact_refs": [],
      "content": "At retrieval, the EBRPD page posted a blue-green algae Caution Advisory for the East Swim Beach and stated that the West Swim Beach had no water because of low lake levels.",
      "observation_id": "observation-del-valle-ebrpd-water-quality",
      "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 EBRPD page posted a blue-green algae Caution Advisory for the East Swim Beach and stated that the West Swim Beach had no water because of low lake levels.",
    "observation_id": "observation-del-valle-ebrpd-water-quality",
    "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"
    }
  ]
}