{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -118.38611, 34.26056 ] }, "properties":{ "provider":"SPL", "code":"Hansen", "slug":"hansen", "elevation":990.0, "horizontal_datum":"WGS84", "vertical_datum":"NGVD29", "state":"CA", "kind":"PROJECT", "nearest_city":"San Fernando", "public_name":"Hansen Dam", "location_code":518145, "nsid":null, "aliases":{ "NIDID":"CA10019" }, "timeseries":[ { "tsid":"Hansen.Elev.Inst.0.0.Rescal", "label":"Elevation", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-04-14T14:30:00Z", "latest_value":991.25, "delta24h":null, "sort_order":1, "results":null }, { "tsid":"Hansen US.Flow.Ave.0.0.Rescal", "label":"Inflow", "base_parameter":"Flow", "parameter":"Flow", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-04-14T14:30:00Z", "latest_value":248.0, "delta24h":null, "sort_order":6, "results":null }, { "tsid":"Hansen.Flow.Inst.0.0.Rescal", "label":"Outflow", "base_parameter":"Flow", "parameter":"Flow", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-04-14T14:30:00Z", "latest_value":248.0, "delta24h":null, "sort_order":7, "results":null }, { "tsid":"Hansen.Stor.Inst.0.0.Rescal", "label":"Flood Storage", "base_parameter":"Stor", "parameter":"Stor", "unit":"ac-ft", "unit_long_name":"Acre-feet", "latest_time":"2026-04-14T14:30:00Z", "latest_value":21.0, "delta24h":null, "sort_order":11, "results":null }, { "tsid":"Hansen.Precip.Inst.~15Minutes.0.GOES-rev", "label":"Precipitation", "base_parameter":"Precip", "parameter":"Precip", "unit":"in", "unit_long_name":"Inches", "latest_time":"2026-04-14T22:00:00Z", "latest_value":23.29, "delta24h":null, "sort_order":16, "results":null } ], "name":"Hansen Dam", "hasResopsAverages":"false", "nidId":"CA10019", "nidid":"", "levels":[ { "slug":"elev.bottom of flood", "label":"Bottom of Flood", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Hansen.Elev.Inst.0.Bottom of Flood", "latest_value":1010.5, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.streambed", "label":"Streambed", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Hansen.Elev.Inst.0.Streambed", "latest_value":990, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of dam", "label":"Top of Dam", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Hansen.Elev.Inst.0.Top of Dam", "latest_value":1087, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of debris pool", "label":"Top of Debris Pool", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Hansen.Elev.Inst.0.Top of Debris Pool", "latest_value":1010.5, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of flood", "label":"Top of Flood", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Hansen.Elev.Inst.0.Top of Flood", "latest_value":1060, "units":"ft", "units_long_name":"Feet" }, { "slug":"stor.bottom of flood", "label":"Bottom of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Hansen.Stor.Inst.0.Bottom of Flood", "latest_value":3756, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.streambed", "label":"Streambed", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Hansen.Stor.Inst.0.Streambed", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of dam", "label":"Top of Dam", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Hansen.Stor.Inst.0.Top of Dam", "latest_value":59299, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of debris pool", "label":"Top of Debris Pool", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Hansen.Stor.Inst.0.Top of Debris Pool", "latest_value":3756, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Hansen.Stor.Inst.0.Top of Flood", "latest_value":33348, "units":"ac-ft", "units_long_name":"Acre-feet" } ], "id":549826, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":97, "damLength":10475, "distance":null, "drainageArea":152, "eapId":1, "dsacAssignedDate":"2021-12-02T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2025-04-22T12:00:00.000Z", "eapLastRevDate":"2019-10-31T12:00:00.000Z", "enforcementAuthorityId":0, "federalId":"CA10019", "oldFederalId":"CA10019", "hazardId":4, "hydraulicHeight":92, "inspectionAuthorityId":0, "inspectionDate":"2020-11-05T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":0, "latitude":34.2609810290001, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-118.386759104, "maxDischarge":101000, "maxStorage":44990, "nidHeight":97, "nidStorage":44990, "normalStorage":0, "numberOfLocks":0, "operationalStatusDate":"2009-01-26T12:00:00.000Z", "operationalStatusId":2, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":0, "politicalPartyId":null, "privateDamId":null, "projectDescription":"Hansen Dam is located at the northern edge of the San Fernando Valley in the City of Los Angeles, Los Angeles County, California. The project is located on the Tujunga Wash about 1 mile downstream from the confluence of the Big Tujunga and Little Tujunga Washes as they exit the San Gabriel Mountains, and the Angeles National Forrest. The US Army Corps of Engineers (USACE) built the dam in 1940 for the purpose of providing flood control for the lower portions of San Fernando Valley and the city of Los Angeles. Hansen Dam receives inflow from Los Angeles County\u2019s upstream Big Tujunga Dam and is operated in conjunction with the Corps\u2019 Sepulveda Dam as a part of the Los Angeles County Drainage Area (LACDA) system. The dam consists of an earthen embankment dam and saddle dike, gated and ungated outlet works, and an uncontrolled spillway. The dam is 10,475 feet long with a maximum height above streambed of 97 feet. The saddle dike is approximately 1,525 feet long and has a maximum height of approximately 22 feet. Hansen Dam typically has no pool. However, during the rainy season that normally occurs between November and early April there may be a small stream trickling through the dam. The dam contains eight operation gates which allow minor flows to pass through the project.", "riskCharSummary":"Dams do not eliminate all risk of flooding. USACE works to address all types of flood risk associated with the dam. Dams have limited capacity to store water. Water may be released through the dam to manage water levels up or downstream or to relieve pressure on the dam to maintain its structural integrity. Severe weather events that bring inconsistent or larger amounts of water into the system can also lead to dam releases or in some cases overwhelm and lead to issues occurring at a dam. More detail related to this specific dam will be added at a future time.", "riskManagementMeasures":"USACE manages dam-related flood risks by continually monitoring the condition and health of the dam, prioritizing activities that will most impact the risks, and engaging upstream and downstream emergency managers and members of the public to raise awareness of the dam and support actions to prepare and be ready to respond in the case of a dam-related emergency. USACE works closely with local emergency managers to share what is known about the dam and support the development of local emergency and evacuation plans. USACE regularly updates the emergency action plan for the dam. Regular maintenance and repairs are performed as needed to keep the dam functioning properly. More detail related to this specific dam will be added at a future time.", "riverName":"TUJUNGA WASH", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":284, "stateFedId":"CA10019", "stateRegulatoryAgency":null, "stateRegulatedId":0, "structuralHeight":null, "submitDate":"2023-02-16T17:25:38.745Z", "surfaceArea":1, "volume":0, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1940, "congDist":"Congressional District 30, California", "city":"LOS ANGELES", "county":"Los Angeles", "aiannh":null, "websiteUrl":"https://www.usace.army.mil/Missions/Civil-Works/Dam-Safety-Program/Article/2870967/dam-safety-program/", "coreTypeIds":null, "damTypeIds":"8", "fedConstructionIds":"1", "fedDesignIds":"1", "fedFundingIds":"1", "fedInspectionIds":"1", "fedOperationIds":"1", "fedOtherIds":"1", "fedOwnerIds":"1", "fedRegulatoryIds":"1", "formerNames":null, "foundationTypeIds":null, "nonFederalDamOnFederalId":0, "designerNames":"CESPL", "otherNames":"Hansen Reservoir", "ownerNames":"USACE - Los Angeles District", "ownerTypeIds":"3", "primaryDamTypeId":8, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;5", "dsacId":3, "femaRegion":"9", "lastEapExcerDate":"2023-06-05T12:00:00.000Z", "dataUpdated":"2025-04-23T12:00:00.000Z", "usaceDistrict":"Los Angeles District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"180701", "doi_region":"LCB", "doi_region_name":"Lower Colorado Basin", "doi_region_number":8 }, "id":518145, "links":[ { "type":"application/json", "rel":"root", "title":"The landing page of this server as JSON", "href":"https://api.wwdh.internetofwater.app?f=json" }, { "type":"text/html", "rel":"root", "title":"The landing page of this server as HTML", "href":"https://api.wwdh.internetofwater.app?f=html" }, { "rel":"self", "type":"application/geo+json", "title":"This document as JSON", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/518145?f=json" }, { "rel":"alternate", "type":"application/ld+json", "title":"This document as RDF (JSON-LD)", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/518145?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/518145?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }