{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -89.77056, 33.80861 ] }, "properties":{ "provider":"MVK", "code":"Grenada Lake", "slug":"grenada%20lake", "elevation":0.0, "horizontal_datum":"NAD27", "vertical_datum":"NGVD29", "state":"MS", "kind":"PROJECT", "nearest_city":"Grenada", "public_name":"Grenada Lake", "location_code":355013, "nsid":null, "aliases":{ "NIDID":"MS01494", "CWMS Legacy Naming":"Grenada Lake", "CWMS Standard Naming":"Grenada Lake", "DCP Platform ID":"CE417BB6", "SHEF Location ID":"CE417BB6" }, "timeseries":[ { "tsid":"Grenada Lake.Elev.Inst.1Hour.0.Guide Curve", "label":"Elevation Rule Curve", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-26T00:00:00Z", "latest_value":211.45, "delta24h":null, "sort_order":2, "results":null }, { "tsid":"Grenada Lake.Flow.Inst.1Hour.0.Total Gate Flow", "label":"Outflow", "base_parameter":"Flow", "parameter":"Flow", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-08-25T21:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":7, "results":null }, { "tsid":"Grenada 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":"2026-08-25T21:00:00Z", "latest_value":381553.99, "delta24h":null, "sort_order":11, "results":null }, { "tsid":"Grenada Lake-Tailwater.Elev.Inst.1Hour.0.DCP-rev", "label":"Elevation Tailwater", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T21:00:00Z", "latest_value":159.3, "delta24h":null, "sort_order":3, "results":null }, { "tsid":"Grenada Lake-Spillway.Flow.Inst.1Hour.0.Spillway Flow", "label":"Surcharge Release", "base_parameter":"Flow", "parameter":"Flow", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-08-25T21:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":8, "results":null }, { "tsid":"Grenada Lake-Tailwater.Stage.Inst.1Hour.0.DCP-rev", "label":"Stage Tailwater", "base_parameter":"Stage", "parameter":"Stage", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T21:00:00Z", "latest_value":159.3, "delta24h":null, "sort_order":5, "results":null }, { "tsid":"Grenada Lake.Elev.Inst.1Hour.0.DCP-rev", "label":"Elevation", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T21:00:00Z", "latest_value":209.72, "delta24h":null, "sort_order":1, "results":null }, { "tsid":"Grenada Lake.Stor.Inst.1Hour.0.DCP-rev", "label":"Conservation Storage", "base_parameter":"Stor", "parameter":"Stor", "unit":"ac-ft", "unit_long_name":"Acre-feet", "latest_time":"2026-08-25T21:00:00Z", "latest_value":381553.99, "delta24h":null, "sort_order":13, "results":null }, { "tsid":"Grenada Lake.Flow-In.Ave.1Hour.0.24 Hour Average", "label":"Inflow", "base_parameter":"Flow", "parameter":"Flow-In", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-08-25T20:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":6, "results":null }, { "tsid":"Grenada Lake.Precip.Total.1Hour.1Hour.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":"Grenada Lake", "hasResopsAverages":"true", "nidId":"MS01494", "nidid":"", "levels":[ { "slug":"elev.streambed", "label":"Streambed", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grenada Lake.Elev.Inst.0.Streambed", "latest_value":160, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of conservation", "label":"Top of Conservation", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grenada Lake.Elev.Inst.0.Top of Conservation", "latest_value":193, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of dam", "label":"Top of Dam", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grenada Lake.Elev.Inst.0.Top of Dam", "latest_value":256, "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":"Grenada Lake.Elev.Inst.0.Top of Flood Control", "latest_value":231, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of guide curve", "label":"Top of Guide Curve", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grenada Lake.Elev.Inst.0.Top of Guide Curve", "latest_value":211.73, "units":"ft", "units_long_name":"Feet", "type":"REGULAR" }, { "slug":"elev.top of inactive", "label":"Top of Inactive", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grenada Lake.Elev.Inst.0.Top of Inactive", "latest_value":169, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of surcharge", "label":"Top of Surcharge", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grenada Lake.Elev.Inst.0.Top of Surcharge", "latest_value":247.5, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stor.streambed", "label":"Streambed", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grenada Lake.Stor.Inst.0.Streambed", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of conservation", "label":"Top of Conservation", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grenada Lake.Stor.Inst.0.Top of Conservation", "latest_value":85700, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of dam", "label":"Top of Dam", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grenada Lake.Stor.Inst.0.Top of Dam", "latest_value":3734500, "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":"Grenada Lake.Stor.Inst.0.Top of Flood Control", "latest_value":1337400, "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":"Grenada Lake.Stor.Inst.0.Top of Surcharge", "latest_value":2722100, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" } ], "id":550300, "associatedStructuresCount":1, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":80, "damLength":13900, "distance":2, "drainageArea":1320, "eapId":1, "dsacAssignedDate":"2022-05-23T12:00:00.000Z", "eapMeetsGuidelinesId":0, "emergencyContactsUpdated":"2025-04-16T12:00:00.000Z", "eapLastRevDate":"2021-08-08T12:00:00.000Z", "enforcementAuthorityId":1, "federalId":"MS01494", "oldFederalId":"MS01494", "hazardId":4, "hydraulicHeight":97, "inspectionAuthorityId":1, "inspectionDate":"2020-09-02T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":1, "latitude":33.821629419, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-89.7723936899999, "maxDischarge":52000, "maxStorage":2722100, "nidHeight":103, "nidStorage":2722100, "normalStorage":85700, "numberOfLocks":0, "operationalStatusDate":"2022-05-23T12:00:00.000Z", "operationalStatusId":1, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":1, "politicalPartyId":null, "privateDamId":null, "projectDescription":"The U.S Army Corps of Engineers (USACE) completed Grenada Dam in 1954 across the Yalobusha River and continues the ownership, maintenance, and operation of the facility today. The dam helps to control flooding along the Yazoo River Basin for more than 50,000 residents and more than 20,000 homes and businesses totaling nearly $3 Billion. The dam also provides water-based and other outdoor recreational activities. The 80-foot-tall, earthen-filled dam is located three miles upstream of Grenada, MS and is approximately 13,900 feet (over 2.5 miles) long. The Coffeeville Levee near Coffeeville, MS is a feature of the Grenada Dam Project, and it works to protect Coffeeville from Grenada Lake during high water events. Please refer to the Coffeeville Levee (NID ID: MS01494S001) for more information about that structure. \n\nGrenada Dam and Reservoir is managed throughout the year to store and slowly release water to help keep the Yalobusha River within its banks and to reduce the peak flow of rainfall runoff. The lake is drawn down during the fall and winter months to provide needed storage for when rains are prevalent. The lake is allowed to fill during the spring and summer months to provide recreational opportunities to the visiting public. The lake is operated in this manner on a yearly basis following the Water Control Plan for the project.\n\nReservoir water is released through three gated outlet tunnels into the Yalobusha River. These outlets can release enough water to fill an Olympic size swimming pool in 8 seconds. The dam's emergency spillway is located on the south side of the dam and is designed to pass high volumes of flood waters to keep the dam from being overtopped and breaking. In the unlikely event that water exceeds safe levels, the spillway would pass this water over a concrete rim and down a 200-foot wide concrete slope into the spillway outlet channel and eventually back into the Yalobusha River. This emergency spillway can release enough water to fill an Olympic size swimming pool in 2 seconds. Grenada Lake has overflowed the emergency spillway 6 times since the dam was constructed. The most recent overflow occurred in 2020.", "riskCharSummary":"While Grenada Dam significantly reduces flood risks for downstream communities, it does not eliminate them. Large, rare storm events can produce more rainfall than the dam and reservoir can safely store, resulting in the need for large water releases or activation of the spillway to prevent overtopping and failure. These releases can cause downstream flooding, particularly in low-lying and agricultural areas along the Yalobusha and Yazoo River systems.\n\nThe most recent Periodic Assessment, completed by USACE in accordance with ER 1110-2-1156, evaluated several potential failure modes (PFMs) for Grenada Dam and the associated Coffeeville Levee. The assessment identified two primary risk drivers at the dam: Backward erosion piping at the outlet works, which could result in loss of material and threaten the stability of the structure, and Uplift pressure under the stilling basin slab, which could damage outlet components and lead to uncontrolled releases.\n\nAlthough the likelihood of these failure modes occurring is considered remote, their consequences could include downstream flooding and potential loss of life, especially near low-lying communities such as Grenada and Coffeeville. Continued monitoring and mitigation efforts are essential to maintaining public safety.\n\nThe Coffeeville Levee was assessed as a low-risk (DSAC 5) structure. The primary concern is overtopping during extreme flood events. Although no loss of life is expected under such a scenario, prolonged flooding of the town and surrounding areas could occur.", "riskManagementMeasures":"USACE works to reduce the risks posed to the community by Grenada Dam. USACE operations and engineering staff routinely conduct detailed inspections of the project to ensure the integrity of the dam, identify new deficiencies, and monitor known deficiencies. The dam has a robust instrumentation and monitoring program that allows USACE staff to regularly monitor the dam\u2019s performance under changing pool conditions. The dam\u2019s Emergency Action Plan is updated regularly, and the emergency notification charts are updated annually. This plan has been coordinated with state and local Emergency Management Agencies to help improve their dam incident response planning and preparedness responsibilities. Emergency exercises are routinely held with local and state emergency responders and stakeholders to enhance the local communities\u2019 emergency response plans. Regular maintenance and repairs are performed as needed to keep the dam functioning properly. USACE has made interim repairs to the drainage system, outlet channel, and toe ditch to reduce risk of failure.", "riverName":"YALOBUSHA RIVER", "separateStructuresCount":1, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":200, "stateFedId":"MS01494", "stateRegulatoryAgency":"MS DEPARTMENT OF ENVIRONMENTAL QUALITY", "stateRegulatedId":1, "structuralHeight":103, "submitDate":"2023-09-10T21:03:29.730Z", "surfaceArea":9800, "volume":9600000, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1954, "congDist":"Congressional District 02, Mississippi", "city":"GRENADA", "county":"Grenada", "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":"3", "nonFederalDamOnFederalId":0, "designerNames":"CEMVK", "otherNames":"Grenada Lake", "ownerNames":"USACE - Vicksburg District", "ownerTypeIds":"3", "primaryDamTypeId":8, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;5", "dsacId":4, "femaRegion":"4", "lastEapExcerDate":"2015-09-22T12:00:00.000Z", "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":"080302", "doi_region":null, "doi_region_name":"Mississippi Basin", "doi_region_number":4, "thirtyYearAverage":632.8352, "tenthPercentile":440.8232, "ninetiethPercentile":856.0062 }, "id":355013, "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/355013?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/355013?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/355013?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }