{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -93.11292, 34.21499 ] }, "properties":{ "provider":"MVK", "code":"Degray Lake", "slug":"degray%20lake", "elevation":0.0, "horizontal_datum":"NAD27", "vertical_datum":"NGVD29", "state":"AR", "kind":"PROJECT", "nearest_city":"Hot Springs", "public_name":"Degray Lake", "location_code":11128013, "nsid":null, "aliases":{ "CWMS Legacy Naming":"Degray Lake", "SHEF Location ID":"CE40AF24", "NIDID":"AR00151", "DCP Platform ID":"CE40AF24", "CWMS Standard Naming":"Degray Lake" }, "timeseries":[ { "tsid":"Degray Lake.%.Inst.1Hour.0.Percent Full", "label":"Percent Flood Pool", "base_parameter":"%", "parameter":"%", "unit":"%", "unit_long_name":"Percent", "latest_time":"2026-08-25T20:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":12, "results":null }, { "tsid":"Degray Lake.Stor.Inst.1Hour.0.DCP-rev", "label":"Flood Storage", "base_parameter":"Stor", "parameter":"Stor", "unit":"ac-ft", "unit_long_name":"Acre-feet", "latest_time":"2026-08-25T20:00:00Z", "latest_value":601102.58, "delta24h":null, "sort_order":11, "results":null }, { "tsid":"Degray Lake.Elev.Inst.1Hour.0.DCP-rev", "label":"Elevation", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T20:00:00Z", "latest_value":403.83, "delta24h":null, "sort_order":1, "results":null }, { "tsid":"Degray Lake.%.Inst.1Hour.0.Percent Full", "label":"Percent Conservation Pool", "base_parameter":"%", "parameter":"%", "unit":"%", "unit_long_name":"Percent", "latest_time":"2026-08-25T20:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":14, "results":null }, { "tsid":"Degray Lake.Precip.Inst.1Hour.0.DCP-rev", "label":"Precipitation", "base_parameter":"Precip", "parameter":"Precip", "unit":"in", "unit_long_name":"Inches", "latest_time":"2026-08-25T20:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":16, "results":null } ], "name":"Degray Lake", "hasResopsAverages":"true", "nidId":"AR00151", "nidid":"", "levels":[ { "slug":"elev.streambed", "label":"Streambed", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Degray Lake.Elev.Inst.0.Streambed", "latest_value":210, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of conservation", "label":"Top of Conservation", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Degray Lake.Elev.Inst.0.Top of Conservation", "latest_value":408, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of dam", "label":"Top of Dam", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Degray Lake.Elev.Inst.0.Top of Dam", "latest_value":453, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of flood control", "label":"Top of Flood Control", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Degray Lake.Elev.Inst.0.Top of Flood Control", "latest_value":423, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of power", "label":"Top of Power", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Degray Lake.Elev.Inst.0.Top of Power", "latest_value":408, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of surcharge", "label":"Top of Surcharge", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Degray Lake.Elev.Inst.0.Top of Surcharge", "latest_value":447.5, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stor.top of conservation", "label":"Top of Conservation", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Degray Lake.Stor.Inst.0.Top of Conservation", "latest_value":654700, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of flood control", "label":"Top of Flood Control", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Degray Lake.Stor.Inst.0.Top of Flood Control", "latest_value":881900, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of power", "label":"Top of Power", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Degray Lake.Stor.Inst.0.Top of Power", "latest_value":654700, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of surcharge", "label":"Top of Surcharge", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Degray Lake.Stor.Inst.0.Top of Surcharge", "latest_value":1377000, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" } ], "id":549789, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":null, "damLength":13200, "distance":7, "drainageArea":453, "eapId":1, "dsacAssignedDate":"2016-12-28T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2025-04-23T12:00:00.000Z", "eapLastRevDate":"1996-12-02T12:00:00.000Z", "enforcementAuthorityId":0, "federalId":"AR00151", "oldFederalId":"AR00151", "hazardId":4, "hydraulicHeight":93, "inspectionAuthorityId":0, "inspectionDate":"2025-06-10T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":0, "latitude":34.2143374500001, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-93.110750684, "maxDischarge":67000, "maxStorage":1377100, "nidHeight":98, "nidStorage":1377100, "normalStorage":654700, "numberOfLocks":0, "operationalStatusDate":"2016-12-28T12:00:00.000Z", "operationalStatusId":1, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":0, "politicalPartyId":null, "privateDamId":null, "projectDescription":"The U.S. Army Corps of Engineers (USACE) completed construction of DeGray Dam in 1971 and continues to own, operate, and maintain the facility. Located on the Caddo River, approximately 7 miles northwest of Arkadelphia, Arkansas, the dam provides critical flood risk reduction, hydroelectric power generation, water supply, and recreational opportunities to the region. The project protects downstream areas including Caddo Valley and Arkadelphia, where flood damage reduction benefits extend to hundreds of residents and vital infrastructure.\n\nDeGray Dam is a 243-foot-tall, earth-fill embankment structure stretching approximately 3,400 feet across the valley floor. It is accompanied by a 13,200-foot-long saddle dike to the east, which helps contain the reservoir pool during high water events. Arkansas Highway 7 crosses over the saddle dike, providing critical transportation access to the area.\n\nWater is released from the dam through a gated concrete outlet works structure located in the right abutment. The outlet system includes a 29-foot-diameter flood control tunnel and branch tunnels that feed a powerhouse with a 40,000-kilowatt conventional unit and a 28,000-kilowatt pump-turbine unit, which produces enough power to power 5 million homes for one day. \nAn unlined overflow spillway is located 4,000 feet east of the dam on a natural sandstone saddle. Though never used since construction, this broad-crested spillway can safely pass extreme flood flows without overtopping the dam. The combination of outlet works, and spillway ensures safe passage of floodwaters in accordance with USACE standards.\n\nThe DeGray embankment is constructed of a zoned earth-fill design with a central impervious clay core and random material outer shells. While the dam performs well under current loading, localized areas of concern such as potential erosion at the abutment contacts and low-lying sections of the crest have been identified through USACE inspections. A paved crest roadway, downstream sand filter drains, and a robust instrumentation system enhance long-term performance monitoring. The dam remains in overall good condition and continues to provide vital risk reduction and multi-purpose benefits to central Arkansas.\n\nTo prepare your family against possible flooding, please visit the National Inventory of Dams (NID) website to see maps showing the potential extent of flooding locations if Blakely Mountain Dam were to breach.", "riskCharSummary":"While DeGray Dam significantly reduces flood risks for communities downstream\u2014particularly Caddo Valley and portions of Arkadelphia\u2014it does not eliminate those risks entirely. Flooding can still occur even when the dam operates exactly as designed. Unlikely but possible large rainfall events could generate inflows that exceed the dam\u2019s outlet capacity. In these rare cases, the overflow spillway\u2014an unlined channel carved into natural sandstone east of the dam\u2014could activate to safely pass excess water and prevent overtopping of the dam itself.\n\nIf the overflow spillway were to activate, floodwaters could affect low-lying areas downstream, including farmland and infrastructure along the Caddo River. During these scenarios, floodwaters would also back up tributaries such as Caney Creek, with water levels potentially reaching vulnerable facilities near the Caddo Valley community. Although life loss is not expected in non-breach events, homes, roadways, and emergency services may be affected, especially if warning times are short or public response is delayed.\n\nUSACE has modeled numerous extreme event scenarios and determined that failure of DeGray Dam, although unlikely, would have serious consequences. In a breach scenario, deep and fast-moving floodwaters would reach Caddo Valley within approximately one hour with expected life loss consequences. These floodwaters would be capable of destroying homes, bridges, highways, and critical infrastructure, with impacts reaching as far as Arkadelphia and even low-lying parts of Camden, 78 miles downstream.\n\nThe most significant failure risks involve internal erosion at abutment contacts or cracking from differential settlement. These potential failure modes are considered unlikely but if they were to occur, they could develop slowly, providing time for detection and emergency action. \n\nDeGray Dam has performed reliably since its completion in 1971 and is currently classified as a DSAC 4 (Low Urgency) facility by USACE. This means that while the probability of failure is low, the dam\u2019s high hazard classification requires ongoing vigilance. Residents downstream should remain informed and follow all instructions from local emergency officials in the rare event of severe flooding. USACE encourages residents to review flood inundation maps available through the National Inventory of Dams (NID) and local emergency management offices.", "riskManagementMeasures":"To ensure DeGray Dam continues to safely manage floodwaters and support its authorized project purposes\u2014including hydropower generation, water supply, and recreation\u2014USACE relies on state-of-the-art modeling tools, real-time rainfall forecasts, and upstream stream gauge data to predict lake elevations and anticipate downstream impacts. USACE routinely inspects the dam, collects and analyzes instrumentation data, and reassesses risks as new information becomes available.\n\nIn response to risks identified in the most recent Periodic Assessment, USACE has recommended several targeted actions to maintain the long-term integrity of the dam and reduce risk. These include surveying and verifying crest elevations on the saddle dike to ensure adequate freeboard during high pool events and improving the visibility and functionality of piezometer monitoring systems across the project. Monitoring of abutment contacts and seepage areas continues on a routine basis to detect any potential early signs of internal erosion, although none have been observed to date.\n\nUSACE has also identified and plans to address minor maintenance items such as vegetation management on embankment slopes, removal of obstructions from rockfill blankets, and updating corrosion protection measures on mechanical gate systems. The Water Control Manual will be revised to ensure reservoir operations reflect the latest hydrologic conditions and risk-informed decision-making.\n\nWhile no structural repairs are currently deemed necessary, USACE has implemented proactive monitoring strategies and stands ready to escalate surveillance and operational controls during flood events. In such cases, trained personnel initiate 24-hour monitoring in accordance with the dam\u2019s Emergency Action Plan (EAP).\nUSACE continues to coordinate closely with the National Weather Service (NWS), U.S. Geological Survey (USGS), Arkansas Division of Emergency Management (ADEM), and local emergency responders. Joint emergency exercises are held periodically to ensure preparedness and improve community response in the event of a dam-related incident. This multi-agency collaboration ensures timely warnings and protective actions can be taken if extreme weather or operational challenges arise.", "riverName":"CADDO RIVER", "separateStructuresCount":2, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":0, "stateFedId":"AR00151", "stateRegulatoryAgency":null, "stateRegulatedId":0, "structuralHeight":98, "submitDate":"2023-09-10T21:23:43.313Z", "surfaceArea":13400, "volume":6831000, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1969, "congDist":"Congressional District 04, Arkansas", "city":"CADDO VALLEY", "county":"Clark", "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":null, "foundationTypeIds":"1", "nonFederalDamOnFederalId":0, "designerNames":"CEMVK", "otherNames":"DeGray Lake", "ownerNames":"USACE - Vicksburg District", "ownerTypeIds":"3", "primaryDamTypeId":8, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;5;6;8", "dsacId":4, "femaRegion":"6", "lastEapExcerDate":"2025-03-04T12:00:00.000Z", "dataUpdated":"2025-07-01T12:00:00.000Z", "usaceDistrict":"Vicksburg District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"080401", "doi_region":null, "doi_region_name":"Mississippi Basin", "doi_region_number":4, "thirtyYearAverage":704.9007, "tenthPercentile":666.5926, "ninetiethPercentile":760.1104 }, "id":11128013, "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/11128013?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/11128013?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/11128013?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }