{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -100.48139, 31.48444 ] }, "properties":{ "provider":"SWF", "code":"SAGT2", "slug":"sagt2", "elevation":0.0, "horizontal_datum":"", "vertical_datum":"NGVD29", "state":"TX", "kind":"PROJECT", "nearest_city":"San Angelo, TX", "public_name":"O.C. 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Fisher Lake", "hasResopsAverages":"true", "nidId":"TX00012", "nidid":"", "levels":[ { "slug":"elev.bottom of inactive", "label":"Bottom of Inactive", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Bottom of Inactive", "latest_value":1839, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.design capacity", "label":"Design Capacity", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Design Capacity", "latest_value":1958, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.spillway crest", "label":"Spillway Crest", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Spillway Crest", "latest_value":1938.5, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.streambed", "label":"Streambed", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Streambed", "latest_value":1836, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of conservation", "label":"Top of Conservation", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Top of Conservation", "latest_value":1908, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of dam", "label":"Top of Dam", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Top of Dam", "latest_value":1964, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of flood", "label":"Top of Flood", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Top of Flood", "latest_value":1938.5, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of inactive", "label":"Top of Inactive", "parameter":"Elev", "base_parameter":"Elev", "tsid":"SAGT2.Elev.Inst.0.Top of Inactive", "latest_value":1840, "units":"ft", "units_long_name":"Feet" }, { "slug":"stor.bottom of inactive", "label":"Bottom of Inactive", "parameter":"Stor", "base_parameter":"Stor", "tsid":"SAGT2.Stor.Inst.0.Bottom of Inactive", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.spillway crest", "label":"Spillway Crest", "parameter":"Stor", "base_parameter":"Stor", "tsid":"SAGT2.Stor.Inst.0.Spillway Crest", "latest_value":396400, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.streambed", "label":"Streambed", "parameter":"Stor", "base_parameter":"Stor", "tsid":"SAGT2.Stor.Inst.0.Streambed", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of conservation", "label":"Top of Conservation", "parameter":"Stor", "base_parameter":"Stor", "tsid":"SAGT2.Stor.Inst.0.Top of Conservation", "latest_value":115743, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"SAGT2.Stor.Inst.0.Top of Flood", "latest_value":392716, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of inactive", "label":"Top of Inactive", "parameter":"Stor", "base_parameter":"Stor", "tsid":"SAGT2.Stor.Inst.0.Top of Inactive", "latest_value":1, "units":"ac-ft", "units_long_name":"Acre-feet" } ], "id":550036, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":128, "damLength":40885, "distance":null, "drainageArea":1511, "eapId":1, "dsacAssignedDate":"2020-05-04T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2024-09-10T12:00:00.000Z", "eapLastRevDate":"2020-09-18T12:00:00.000Z", "enforcementAuthorityId":0, "federalId":"TX00012", "oldFederalId":"TX00012", "hazardId":4, "hydraulicHeight":122, "inspectionAuthorityId":0, "inspectionDate":"2023-12-13T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":0, "latitude":31.4843256940001, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-100.481898322, "maxDischarge":356200, "maxStorage":766000, "nidHeight":130, "nidStorage":766000, "normalStorage":115700, "numberOfLocks":0, "operationalStatusDate":"2020-05-04T12:00:00.000Z", "operationalStatusId":2, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":0, "politicalPartyId":null, "privateDamId":null, "projectDescription":"The U.S. Army Corps of Engineers (USACE) completed construction of O.C. Fisher Dam in March 1951 as a response to historical flooding in the 1930\u2019s that resulted in millions of dollars in property damage to the City of San Angelo. It is located 2 miles west of the city of San Angelo in Tom Green County, Texas. The dam reduces the risk of downstream flooding along the North Concho River by holding back waters during heavy rain events. Currently, the reservoir remains dry most of the time due to the change in upstream vegetation as well as an increase in groundwater pumping. It only fills during heavy rains. The dam is an earthen dam, approximately seven miles long, with a concrete spillway that holds water to 25-feet below the top of the dam; however, there are no gates to regulate water flows when the reservoir rises above that level. Any water above that level will flow downstream. The dam also has gated concrete conduits, or pipes through the dam, for releasing additional water in a regulated manner during and after flood events. The conduits are not used during periods of drought. Additional benefits of the dam are recreation and fish and wildlife.", "riskCharSummary":"Although O.C. Fisher Dam reduces the risk of flooding to downstream communities, the dam does not eliminate the risk of flooding. O.C. Fisher Dam is designed to reduce the peak flooding levels downstream without risking the structural integrity of the dam. USACE completed a risk assessment in May 2020 and classified the risks associated with the project as high. This classification is based on the large population that lives immediately downstream of the dam in San Angelo, Texas, as well as along the Concho and Colorado Rivers and their tributaries, including the cities of Austin and Bay City, Texas. The most likely scenario that could result in downstream flooding is high volume releases from O.C. Fisher Dam through the un-gated spillway during high water events. These surcharge operational releases occur when the reservoir's flood storage capacity is exceeded and excess water flows through the spillway. Surcharge releases through the spillway during the largest expected flood in the watershed would put thousands of people at risk and flood waters could be as deep as a one-story building. Two unlikely, but far more devastating, scenarios than presented above that would produce significant downstream flooding are breach of the dam due to overtopping of the dam and spillway erosion leading to breach. Although the lake does not typically hold water, in the case of an extremely rare but large rain event, the dam could potentially overtop, which could cause erosion of the embankment, and breach of the dam would be possible. In addition, large spillway flows could cause erosion in the channel downstream and potentially undermine the spillway control structure leading to a breach of the spillway structure. In either scenario, downstream flooding in San Angelo would occur within an hour of breach and could be as deep as a two-story structure, destroying buildings and critical infrastructure. In addition, some evacuation routes would be under water, increasing evacuation distances. In either of these unlikely scenarios, failure of O.H. Ivie Reservoir (Simon Freese Dam, NID ID TX06386), located downstream of O.C. Fisher Dam, could also occur due to overtopping of the dam. Although the large downstream communities have well-practiced emergency action plans, and local emergency managers are aware of the unlikely potential for dam failure, breach of the dam would result in significant loss of life and severe economic damages.", "riskManagementMeasures":"In order to lower the risks associated with the dam, inspections and monitoring are performed regularly to ensure the health and safety of the dam. Surveillance and inspections are increased as the lake elevation rises. Routine maintenance and dam safety monitoring are performed to ensure the dam is functioning as designed. Portions of the embankment crest road were repaired in 2019 to prevent water from seeping through the earthen embankment, causing voids as the soil erodes. The remainder of the crest road will be repaired as funds are available. The Emergency Action Plan is updated and exercised annually, improving emergency response and coordination between USACE elements and downstream federal, state, county, city agencies, and stakeholders. USACE also communicates risks associated with O.C. Fisher Dam annually with stakeholders and Emergency Managers. A study is planned for early 2022 to further analyze the dam risk and, in the process, develop a list of suggested ways to further reduce the risk posed by the dam.", "riverName":"CONCHO RIVER", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":1150, "stateFedId":"TX00012", "stateRegulatoryAgency":null, "stateRegulatedId":0, "structuralHeight":130, "submitDate":"2023-02-24T00:00:00.000Z", "surfaceArea":5400, "volume":11516600, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1952, "congDist":"Congressional District 11, Texas", "city":"SAN ANGELO", "county":"Tom Green", "aiannh":null, "websiteUrl":"https://www.usace.army.mil/Missions/Civil-Works/Dam-Safety-Program/Article/2870967/dam-safety-program/", "coreTypeIds":"3", "damTypeIds":"8", "fedConstructionIds":"1", "fedDesignIds":"1", "fedFundingIds":"1", "fedInspectionIds":"1", "fedOperationIds":"1", "fedOtherIds":"1", "fedOwnerIds":"1", "fedRegulatoryIds":"1", "formerNames":"San Angelo Dam", "foundationTypeIds":"1;3", "nonFederalDamOnFederalId":0, "designerNames":"CESWF", "otherNames":"O.C. Fisher Lake", "ownerNames":"USACE - Fort Worth District", "ownerTypeIds":"3", "primaryDamTypeId":8, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;4;5;8", "dsacId":2, "femaRegion":"6", "lastEapExcerDate":"2025-02-26T12:00:00.000Z", "dataUpdated":"2025-06-16T12:00:00.000Z", "usaceDistrict":"Fort Worth District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"120901", "doi_region":"ART", "doi_region_name":"Arkansas-Rio Grande-Texas Gulf", "doi_region_number":6, "thirtyYearAverage":15.4676, "tenthPercentile":1.4215, "ninetiethPercentile":36.0899 }, "id":207048, "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/207048?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/207048?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/207048?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }