{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -105.06208, 39.55872 ] }, "properties":{ "provider":"NWO", "code":"CHFI", "slug":"chfi", "elevation":5432.0, "horizontal_datum":"WGS84", "vertical_datum":"LOCAL", "state":"CO", "kind":"PROJECT", "nearest_city":"Columbine", "public_name":"Chatfield Dam & Reservoir", "location_code":2526030, "nsid":null, "aliases":{ "NIDID":"CO01281" }, "timeseries":[ { "tsid":"CHFI.Elev.Inst.1Hour.0.Best-NWO", "label":"Elevation", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-04-14T22:00:00Z", "latest_value":5436.44, "delta24h":null, "sort_order":1, "results":null }, { "tsid":"CHFI.Flow-Out.Inst.1Hour.0.Best-NWO", "label":"Outflow", "base_parameter":"Flow", "parameter":"Flow-Out", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-04-14T22:00:00Z", "latest_value":5.63, "delta24h":null, "sort_order":7, "results":null }, { 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"units_long_name":"Feet" }, { "slug":"elev.top of joint use", "label":"Top of Joint Use", "parameter":"Elev", "base_parameter":"Elev", "tsid":"CHFI.Elev.Inst.0.Top of Joint Use", "latest_value":5444, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of surcharge", "label":"Top of Surcharge", "parameter":"Elev", "base_parameter":"Elev", "tsid":"CHFI.Elev.Inst.0.Top of Surcharge", "latest_value":5521.6, "units":"ft", "units_long_name":"Feet" }, { "slug":"stor.spillway crest", "label":"Spillway Crest", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Spillway Crest", "latest_value":236617, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.streambed", "label":"Streambed", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Streambed", "latest_value":80, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of conservation", "label":"Top of Conservation", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Top of Conservation", "latest_value":50369, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of dam", "label":"Top of Dam", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Top of Dam", "latest_value":386168, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Top of Flood", "latest_value":236617, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of inactive", "label":"Top of Inactive", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Top of Inactive", "latest_value":300, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of joint use", "label":"Top of Joint Use", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Top of Joint Use", "latest_value":50369, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of surcharge", "label":"Top of Surcharge", "parameter":"Stor", "base_parameter":"Stor", "tsid":"CHFI.Stor.Inst.0.Top of Surcharge", "latest_value":353141, "units":"ac-ft", "units_long_name":"Acre-feet" } ], "id":549859, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":null, "damLength":13136, "distance":8, "drainageArea":3018, "eapId":1, "dsacAssignedDate":"2022-05-23T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2023-09-13T12:00:00.000Z", "eapLastRevDate":"2010-06-01T12:00:00.000Z", "enforcementAuthorityId":1, "federalId":"CO01281", "oldFederalId":"CO01281", "hazardId":4, "hydraulicHeight":124, "inspectionAuthorityId":1, "inspectionDate":"2023-06-09T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":1, "latitude":39.557893441, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-105.059406767, "maxDischarge":188000, "maxStorage":355000, "nidHeight":148, "nidStorage":355000, "normalStorage":20000, "numberOfLocks":0, "operationalStatusDate":"2022-05-23T12:00:00.000Z", "operationalStatusId":2, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":1, "politicalPartyId":null, "privateDamId":null, "projectDescription":"Chatfield Dam and Reservoir is owned, operated, and maintained by the U.S. Army Corps of Engineers (USACE). Operating since 1975, it is the second of three \u201ctri-lakes\u201d dams built by USACE to collectively reduce risks from flooding in the Denver metropolitan area. When not operating to reduce flood impacts, USACE manages water releases from the tri-lakes system for recreation, water quality, and to support fish and wildlife.\n\nThe dam consists of an earthen embankment, an outlet structure for releasing stored water, and a spillway over which excess water can flow during times of extreme runoff from rain and snowmelt. During normal operations, the outlet structure provides water to downstream users and releases are generally less than 500 cubic feet per second (cfs) (one cubic foot of water is equal to 7.5 gallons). As operations shift to reducing flood risks during periods of high runoff, the outlet structure is used to manage the reservoir elevation and can release up to 8,400 cfs. When reservoir levels from extreme storms or snowmelt exceed the outlet structure\u2019s release capacity, water can flow through the spillway to reduce the likelihood of water flowing over the embankment (overtopping), which can lead to dam failure, or breach. The spillway was designed to additionally release up to 184,000 cfs. This large but controlled, intentional flow is called a \u201cnon-breach\u201d release. The reservoir has never been high enough for spillway flow. \n\nFor perspective, the largest release of water from Chatfield Dam as a result of flooding was approximately 3,350 cfs from the outlet structure in 1995. It is important to understand that the dam is designed to release far more water when necessary and these large releases can occur with minimal to no warning, even with warning systems in place.", "riskCharSummary":"Although Chatfield Dam continues to reliably reduce floods, it alone cannot eliminate the risk of flooding (nor can the system of dams in which it operates). While unlikely, a non-breach release when the reservoir is full is critical to reduce the chance of dam overtopping, even if streams and rivers below the dam have reached or exceeded their capacity. Impacts on downstream populations and structures would be overwhelming, but a breach would allow water stored behind the dam to significantly intensify downstream flooding.\n\nWhen USACE last assessed the dam\u2019s ability to meet flood risk management goals, it was determined that the primary threats that could lead to a breach during an extreme flood, with the reservoir at or near its maximum storage level, are overtopping and damage to the spillway during non-breach releases. Although these scenarios are very unlikely, failure of the dam or spillway would result in catastrophic flooding with swift, deep, and life-threatening floodwaters in many parts of the Denver metropolitan area and communities along the South Platte River. This would substantially impact property, the economy, and critical infrastructure (such as power and water utilities, transportation systems, and commercial and industrial facilities). \n \nUSACE categorized the risk associated with Chatfield Dam as \u201chigh\u201d among its more than 700 dams due\u2013should a breach occur-to the consequences to the highly urbanized downstream communities where the population has significantly increased since the dam was built. This database and the accompanying inundation maps provide additional details, including consequences for a range of release volumes, non-breach releases, and dam failure. For more information on the USACE Dam Safety Program and risk assessments, visit: https://www.usace.army.mil/Missions/Civil-Works/Dam-Safety-Program.", "riskManagementMeasures":"Ongoing Actions: The USACE Dam Safety Program takes proactive steps to reduce risk to life, property, and the environment during both normal operations and extreme floods. Dam experts routinely monitor and observe the dam, conduct regular maintenance and repairs, and work closely with state and local emergency management agencies with responsibilities in communities potentially affected by high flows to improve preparedness, evacuation planning, and public awareness of flood risks. For more information visit: https://www.usace.army.mil/Missions/Civil-Works/Dam-Safety-Program.\n\nActions at Chatfield Dam: While USACE continues to evaluate how to further reduce the risks associated with Chatfield Dam, several risk reduction measures were completed including repairs to key spillway features to improve performance and improvements to runoff forecast models in coordination with the National Weather Service to accelerate public warnings from local emergency management agencies. \n\nBuilding Awareness: Since dams do not eliminate flood risk, communities downstream of Denver-area dams are encouraged to monitor National Weather Service flood forecasts during periods of heavy rain and snowmelt and learn about potential flood impacts to their family, home, and community. It is important to understand community notification plans, including safe, efficient evacuation routes, and consider preparedness and emergency actions to reduce individual risks.", "riverName":"SOUTH PLATTE RIVER", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":500, "stateFedId":"CO01281", "stateRegulatoryAgency":"DWR", "stateRegulatedId":1, "structuralHeight":148, "submitDate":"2023-02-16T17:25:39.651Z", "surfaceArea":1150, "volume":17255100, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1973, "congDist":"Congressional District 04, Colorado", "city":"DENVER", "county":"Douglas", "aiannh":null, "websiteUrl":"https://www.nwo.usace.army.mil/Missions/Dam-and-Lake-Projects/Tri-Lakes-Projects/Chatfield-Dam/", "coreTypeIds":"3", "damTypeIds":"8", "fedConstructionIds":"1", "fedDesignIds":"1", "fedFundingIds":"1", "fedInspectionIds":"1", "fedOperationIds":"1", "fedOtherIds":"1", "fedOwnerIds":"1", "fedRegulatoryIds":"1", "formerNames":null, "foundationTypeIds":"1;3", "nonFederalDamOnFederalId":0, "designerNames":"CENWO", "otherNames":"Chatfield Lake", "ownerNames":"USACE - Omaha District", "ownerTypeIds":"3", "primaryDamTypeId":8, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;2;5", "dsacId":2, "femaRegion":"8", "lastEapExcerDate":"2025-03-27T12:00:00.000Z", "dataUpdated":"2025-07-03T12:00:00.000Z", "usaceDistrict":"Omaha District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"101900", "doi_region":"UCB", "doi_region_name":"Upper Colorado Basin", "doi_region_number":7, "thirtyYearAverage":32.1598, "tenthPercentile":29.4682, "ninetiethPercentile":33.5244 }, "id":2526030, "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/2526030?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/2526030?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/2526030?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }