{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -82.98429, 38.2535 ] }, "properties":{ "provider":"LRH", "code":"Grayson", "slug":"grayson", "elevation":599.96, "horizontal_datum":"WGS84", "vertical_datum":"NGVD29", "state":"KY", "kind":"PROJECT", "nearest_city":"Grayson", "public_name":"Grayson Lake", "location_code":495108, "nsid":null, "aliases":{ "Local Loc ID":"GRL", "NIDID":"KY03030" }, "timeseries":[ { "tsid":"Grayson-Outflow.Precip.Total.15Minutes.15Minutes.OBS", "label":"Precipitation", "base_parameter":"Precip", "parameter":"Precip", "unit":"in", "unit_long_name":"Inches", "latest_time":"2026-04-14T22:30:00Z", "latest_value":0.0, "delta24h":null, "sort_order":16, "results":null }, { "tsid":"Grayson-Outflow.Elev.Inst.15Minutes.0.OBS", "label":"Elevation Tailwater", "base_parameter":"Elev", "parameter":"Elev", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-04-14T22:30:00Z", "latest_value":586.19, "delta24h":null, 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} ], "name":"Grayson Lake", "hasResopsAverages":"true", "nidId":"KY03030", "nidid":"", "levels":[ { "slug":"elev.bottom of conservation", "label":"Bottom of Conservation", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Bottom of Conservation", "latest_value":598, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.bottom of flood", "label":"Bottom of Flood", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Bottom of Flood", "latest_value":645, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.bottom of normal", "label":"Bottom of Normal", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Bottom of Normal", "latest_value":637, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.streambed", "label":"Streambed", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Streambed", "latest_value":585, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of conservation", 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"units_long_name":"Feet" }, { "slug":"elev.top of normal", "label":"Top of Normal", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Top of Normal", "latest_value":644.88, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of record", "label":"Top of Record", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Top of Record", "latest_value":671.41, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of recreation", "label":"Top of Recreation", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Top of Recreation", "latest_value":645, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of water supply", "label":"Top of Water Supply", "parameter":"Elev", "base_parameter":"Elev", "tsid":"Grayson.Elev.Inst.0.Top of Water Supply", "latest_value":637, "units":"ft", "units_long_name":"Feet" }, { "slug":"stor.bottom of flood", "label":"Bottom of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grayson.Stor.Inst.0.Bottom of Flood", "latest_value":26817, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of dam", "label":"Top of Dam", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grayson.Stor.Inst.0.Top of Dam", "latest_value":259581, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grayson.Stor.Inst.0.Top of Flood", "latest_value":116420, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of inactive", "label":"Top of Inactive", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grayson.Stor.Inst.0.Top of Inactive", "latest_value":30, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of normal", "label":"Top of Normal", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grayson.Stor.Inst.0.Top of Normal", "latest_value":26684.31, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of water supply", "label":"Top of Water Supply", "parameter":"Stor", "base_parameter":"Stor", "tsid":"Grayson.Stor.Inst.0.Top of Water Supply", "latest_value":16223.81, "units":"ac-ft", "units_long_name":"Acre-feet" } ], "id":550417, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":null, "damLength":1460, "distance":6, "drainageArea":196, "eapId":1, "dsacAssignedDate":"2023-11-08T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2024-07-25T12:00:00.000Z", "eapLastRevDate":"2011-07-15T12:00:00.000Z", "enforcementAuthorityId":0, "federalId":"KY03030", "oldFederalId":"KY03030", "hazardId":4, "hydraulicHeight":89, "inspectionAuthorityId":0, "inspectionDate":"2022-10-21T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":0, "latitude":38.253474775, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-82.9845322049999, "maxDischarge":74600, "maxStorage":118990, "nidHeight":120, "nidStorage":118990, "normalStorage":29390, "numberOfLocks":0, "operationalStatusDate":"2023-11-08T12:00:00.000Z", "operationalStatusId":1, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":0, "politicalPartyId":null, "privateDamId":null, "projectDescription":"Grayson Dam was designed and built by the Huntington District of the U.S. Army Corps of Engineers. The project was completed in 1968 under the Flood Control Act of 14 July 1960, Public Law 86-645 and is operated by the U.S. Army Corps of Engineers, Huntington District. Grayson Dam and Lake is located on the Little Sandy River approximately 13 miles upstream of Grayson, Kentucky and approximately 52 river miles upstream of the Little Sandy\u2019s confluence with the Ohio River at Greenup, Kentucky. The primary purpose of Grayson Dam is to reduce flood risks to the residents and businesses downstream. The dam also provides for water supply, water quality control, recreation, and fish and wildlife enhancement. \n\nThe earthen dam has a length of 1,460 feet and a height of 120 feet above the streambed. There is a 200 feet wide, unregulated emergency spillway located to the left of the dam (looking downstream) that would go into operation during extreme flood events to prevent the dam from overtopping. The dam\u2019s primary outlet works tunnel has a maximum discharge capacity of 11,900 cubic feet per second (cfs) and the emergency spillway has a maximum discharge capacity of 95,000 cfs. \n\nThis dam has prevented a total of $451 million dollars of flood damages between its construction and 2021. This means that the dam prevents about $8 million of flood damages every year. Grayson Lake also provides 1.5 million gallons of water per day to the residents of Carter, Elliott, and Lawrence Counties.", "riskCharSummary":"The dam significantly reduces the risk of flooding to surrounding communities. However, it does not entirely eliminate the risk. Although Grayson Dam has historically performed well, extreme rain events may cause areas downstream to be flooded. Even when the dam operates as intended, downstream flooding could still occur in a very large rainfall event. This event could require unusually large quantities of water to be released through the dam gates and emergency spillway. In extreme cases, this flooding could be similar to what was experienced prior to the dam's construction.\n\nThe U.S. Army Corps of Engineers completed a risk assessment for Grayson Dam in 2023 and classified the risk associated with failure as low. This risk categorization is based on the risk of rare storm events occurring which would cause more rainfall than the dam can store safely. During such an event, the open spillway to the south of the dam has the potential to pass over 90,000 cubic feet of water per second. The dam\u2019s spillway would pass these storms to keep the dam from overtopping. \n\nThe Grayson Dam spillway has never been operated, but if it were operated it could result in significant flooding in Grayson and Greenup along I-64. Additionally, backwater flooding could impact Denton upstream. Depending on the amount of water released, significant damages to houses, buildings, factories, roads, bridges, power, and water supply may occur. Critical infrastructure, including roadways (evacuation routes) and bridges along the Little Sandy River may not be passable due to high flood waters during spillway flows. Although the odds of such a storm event occurring are considered extremely unlikely, Grayson Dam has an emergency action plan to lower the risk of life loss if any unanticipated scenarios were to occur.\n\nWhile rare events like these have not occurred to date, if they were to happen, water is likely to reach hillside to hillside quickly and be more than tens of feet deep depending on the location. In the unlikely event Grayson Dam must pass these extreme waters, follow all directions from emergency officials, including evacuation orders. Failure to do so puts you and your family\u2019s lives at risk.", "riskManagementMeasures":"There are numerous activities that U.S. Army Corps of Engineers conducts on a day-to-day basis to help manage risk at Grayson Dam. The dam is well maintained through continuous operations and maintenance activities, and U.S. Army Corps of Engineers conducts detailed inspections of the dam during both normal lake levels and during flood events. Supplementing these inspections, the dam has a specialized instrumentation and monitoring system to allow U.S. Army Corps of Engineers staff to continually evaluate the dam for changing conditions. Risk management and emergency response actions are being supported by conducting emergency exercises and dam safety training with U.S. Army Corps of Engineers staff and local and state emergency responders. Additionally, the dam\u2019s Emergency Action Plan is routinely updated to improve emergency response actions. Flood fighting materials are stored onsite in case of an emergency.", "riverName":"LITTLE SANDY RIVER", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":210, "stateFedId":"KY03030", "stateRegulatoryAgency":null, "stateRegulatedId":0, "structuralHeight":120, "submitDate":"2023-11-29T00:00:00.000Z", "surfaceArea":1510, "volume":1180000, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1968, "congDist":"Congressional District 05, Kentucky", "city":"GRAYSON", "county":"Carter", "aiannh":null, "websiteUrl":"https://www.lrh.usace.army.mil/Missions/Civil-Works/Dam-Safety-Program/", "coreTypeIds":"3", "damTypeIds":"5;8", "fedConstructionIds":"1", "fedDesignIds":"1", "fedFundingIds":"1", "fedInspectionIds":"1", "fedOperationIds":"1", "fedOtherIds":"1", "fedOwnerIds":"1", "fedRegulatoryIds":"1", "formerNames":null, "foundationTypeIds":"1", "nonFederalDamOnFederalId":0, "designerNames":"CELRH", "otherNames":"Grayson Lake", "ownerNames":"USACE - Huntington District", "ownerTypeIds":"3", "primaryDamTypeId":5, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;12;4;5", "dsacId":4, "femaRegion":"4", "lastEapExcerDate":"2024-09-24T12:00:00.000Z", "dataUpdated":"2025-07-15T12:00:00.000Z", "usaceDistrict":"Huntington District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"050901", "doi_region":null, "doi_region_name":"North Atlantic-Appalachian", "doi_region_number":1, "thirtyYearAverage":36.6956, "tenthPercentile":27.6108, "ninetiethPercentile":40.7392 }, "id":495108, "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/495108?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/495108?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/495108?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }