{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -72.36088, 43.60438 ] }, "properties":{ "provider":"NAE", "code":"NHD", "slug":"nhd", "elevation":390.0, "horizontal_datum":"", "vertical_datum":"NGVD29", "state":"VT", "kind":"PROJECT", "nearest_city":"Lebanon", "public_name":"North Hartland Dam", "location_code":8124021, "nsid":null, "aliases":{ "NIDID":"VT00002", "CWMS Legacy Naming":"NHD", "CWMS Standard Naming":"NHD", "USGS Station Number":"01151500" }, "timeseries":[ { "tsid":"NHD.Stage-TAILWATER.Inst.15Minutes.0.DCP-rev", "label":"Stage Tailwater", "base_parameter":"Stage", "parameter":"Stage-TAILWATER", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T21:30:00Z", "latest_value":2.19, "delta24h":null, "sort_order":5, "results":null }, { "tsid":"NHD.Flow-Inflow.Total.15Minutes.6Hours.DCP-rev", "label":"Inflow", "base_parameter":"Flow", "parameter":"Flow-Inflow", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-08-25T21:30:00Z", "latest_value":94.07, "delta24h":null, "sort_order":6, "results":null }, { "tsid":"NHD.Precip.Inst.15Minutes.0.DCP-rev", "label":"Precipitation", "base_parameter":"Precip", "parameter":"Precip", "unit":"in", "unit_long_name":"Inches", "latest_time":"2026-08-25T21:30:00Z", "latest_value":29.73, "delta24h":null, "sort_order":16, "results":null }, { "tsid":"NHD.Stage-Pool.Inst.15Minutes.0.DCP-rev", "label":"Stage", "base_parameter":"Stage", "parameter":"Stage-Pool", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T21:30:00Z", "latest_value":36.36, "delta24h":null, "sort_order":4, "results":null }, { "tsid":"NHD.Stor.Inst.15Minutes.0.DCP-rev", "label":"Flood Storage", "base_parameter":"Stor", "parameter":"Stor", "unit":"ac-ft", "unit_long_name":"Acre-feet", "latest_time":"2026-08-25T21:30:00Z", "latest_value":285.67, "delta24h":null, "sort_order":11, "results":null }, { "tsid":"NHD.Flow.Inst.15Minutes.0.DCP-rev", "label":"Outflow", "base_parameter":"Flow", "parameter":"Flow", "unit":"cfs", "unit_long_name":"Cubic feet per second", "latest_time":"2026-08-25T21:30:00Z", "latest_value":94.07, "delta24h":null, "sort_order":7, "results":null }, { "tsid":"NHD.Temp-Air.Inst.15Minutes.0.DCP-rev", "label":"Air Temperature", "base_parameter":"Temp", "parameter":"Temp-Air", "unit":"F", "unit_long_name":"Fahrenheit", "latest_time":"2026-08-25T21:30:00Z", "latest_value":79.3, "delta24h":null, "sort_order":22, "results":null } ], "name":"North Hartland Dam", "hasResopsAverages":"false", "nidId":"VT00002", "nidid":"", "levels":[ { "slug":"stage.bottom of normal", "label":"Bottom of Normal", "parameter":"Stage-Pool", "base_parameter":"Stage", "tsid":"NHD.Stage-Pool.Inst.0.Bottom of Normal", "latest_value":35, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stage.spillway crest", "label":"Spillway Crest", "parameter":"Stage-Pool", "base_parameter":"Stage", "tsid":"NHD.Stage-Pool.Inst.0.Spillway Crest", "latest_value":156.5, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stage.streambed", "label":"Streambed", "parameter":"Stage-Pool", "base_parameter":"Stage", "tsid":"NHD.Stage-Pool.Inst.0.Streambed", "latest_value":0, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stage.top of dam", "label":"Top of Dam", "parameter":"Stage-Pool", "base_parameter":"Stage", "tsid":"NHD.Stage-Pool.Inst.0.Top of Dam", "latest_value":182, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stage.top of flood", "label":"Top of Flood", "parameter":"Stage-Pool", "base_parameter":"Stage", "tsid":"NHD.Stage-Pool.Inst.0.Top of Flood", "latest_value":156.5, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stage.top of normal", "label":"Top of Normal", "parameter":"Stage-Pool", "base_parameter":"Stage", "tsid":"NHD.Stage-Pool.Inst.0.Top of Normal", "latest_value":38, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"NHD.Stor.Inst.0.Top of Flood", "latest_value":68750, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of normal", "label":"Top of Normal", "parameter":"Stor", "base_parameter":"Stor", "tsid":"NHD.Stor.Inst.0.Top of Normal", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" } ], "id":549886, "associatedStructuresCount":1, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":182, "damLength":1640, "distance":null, "drainageArea":220, "eapId":1, "dsacAssignedDate":"2015-07-11T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2024-12-20T12:00:00.000Z", "eapLastRevDate":"2021-05-04T12:00:00.000Z", "enforcementAuthorityId":0, "federalId":"VT00002", "oldFederalId":"VT00002", "hazardId":4, "hydraulicHeight":177, "inspectionAuthorityId":0, "inspectionDate":"2024-04-09T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":0, "latitude":43.6046691660001, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-72.3608865589999, "maxDischarge":160900, "maxStorage":94600, "nidHeight":182, "nidStorage":94600, "normalStorage":2350, "numberOfLocks":0, "operationalStatusDate":"2015-07-11T12:00:00.000Z", "operationalStatusId":2, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":0, "politicalPartyId":null, "privateDamId":null, "projectDescription":"The U.S. Army Corps of Engineers (USACE) built North Hartland Dam in 1958 to 1961 across the Ottauquechee River. North Hartland Dam holds a 215-acre recreation pool outside of flood events. The dam holds back additional water during flood events and works together with nearby Union Village and North Springfield Dams to reduce the risk of downstream flooding on the Connecticut River. The dam was built in response to the severe flooding that occurred in the region in the 1930\u2019s. Since it began operations, the dam has reduced damage caused by downstream flooding by more than $207 million.\n\nThe dam is made of compacted earth and rock fill and is approximately 18 stories (185 feet) high. A 14.3-foot diameter concrete pipe called a conduit passes through the dam. In 1985, this conduit was lined with a 12-foot diameter stainless steel penstock as part of a downstream hydropower operation. Metal gates at the upstream side of the conduit are opened to allow water to pass through the dam and are closed when water needs to be stored during flood events. To maintain the structural integrity of the dam when the water level in the reservoir gets high, water can also be released across the spillway, a sloped concrete structure located at the north end of the dam. A spillway is similar in concept to a sink overflow that prevents a sink bowl from completely overflowing. The spillway is longer than a football field and approximately two stories below the top of the dam. \n\nA dike, located south of the main dam, is made of compacted earth and rock fill and is approximately 5 stories high. A 3-foot diameter concrete pipe passes through the dike. A metal gate is used to control flow through the dike conduit.", "riskCharSummary":"USACE completed a risk assessment of North Hartland Dam in 2014 and has classified the risks associated with the dam as Moderate. The dam significantly reduces the risk of flooding to surrounding communities. However, it does not entirely eliminate the risk. The most likely scenario that could result in downstream flooding from North Hartland Dam would be an uncontrolled high volume release of water from the dam's spillway during significant storm events. The amount of water being released could be great enough to cause flooding in downstream communities. Such higher releases from the spillway could create conditions similar to how the river might behave during a flood event if the dam did not exist. \n\nThere are also two extremely unlikely, but far more devastating scenarios that would result in failure of the dam or dike and downstream flooding: (1) A flood so large that the capacity of the dam to store water is exceeded, resulting in flows over the top of the dam, even with maximum possible releases being made through the conduit, and (2) water seeping through the dam or dike earth embankments results in voids in these structures as the soil erodes, potentially weakening the structures. Were any of these events to occur, an uncontrolled surge of water would flow out of the reservoir, flooding downstream communities. Hartland, White River Junction, Windsor VT and West Lebanon, NH are the major areas in immediate danger in the event of the flood. Towns and cities further downstream, including Ascutney, Bellows Falls, and Westminster, VT, and Charlestown and Walpole, NH would also be impacted, but less so. \n\nEven though very unlikely, if any of the scenarios described above were to occur, the downstream floodwater would be swift and deep, destroying buildings and key infrastructure, and those caught unaware and/or unable to evacuate could perish. In the less likely dam breach scenarios, the water depth, property damage, and lives lost would likely be far greater than flooding due to spillway discharges. In a worst case scenario, you could see water higher than a three story building.", "riskManagementMeasures":"No emergency situation currently exists at North Hartland Dam. Should a crisis occur, we will use our expertise to quickly find a solution to resume operations. While we cannot completely eliminate risk, we are taking actions to further reduce the risks. We closely monitor the performance of North Hartland Dam and will modify operations if we feel there is risk to the public. We will continue to work closely with state and local emergency managers, conducting emergency exercises, and incorporate any new information into our Emergency Action Plan for the dam. We will also continue our rigorous monitoring and surveillance of the dam, especially during high water events. We closely follow rainfall forecasts to determine when high water events may occur so that necessary flood warnings may be issued in a timely manner. USACE is planning for additional studies to further understand the risk associated with North Hartland Dam, and what, if any, actions can be completed to reduce the risk.", "riverName":"OTTAUQUECHEE RIVER", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":465, "stateFedId":"VT00002", "stateRegulatoryAgency":null, "stateRegulatedId":0, "structuralHeight":182, "submitDate":"2023-02-16T17:25:22.308Z", "surfaceArea":215, "volume":2390840, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1961, "congDist":"Congressional District 00, Vermont", "city":"HARTLAND", "county":"Windsor", "aiannh":null, "websiteUrl":"https://www.nae.usace.army.mil/Missions/Civil-Works/Flood-Risk-Management/Vermont/North-Hartland/", "coreTypeIds":"3", "damTypeIds":"5;8;9", "fedConstructionIds":"1", "fedDesignIds":"1", "fedFundingIds":"1", "fedInspectionIds":"1", "fedOperationIds":"1", "fedOtherIds":"1", "fedOwnerIds":"1", "fedRegulatoryIds":"1", "formerNames":null, "foundationTypeIds":"1;3", "nonFederalDamOnFederalId":0, "designerNames":"CENAE", "otherNames":"North Hartland Lake", "ownerNames":"USACE - New England District", "ownerTypeIds":"3", "primaryDamTypeId":5, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;5;6", "dsacId":3, "femaRegion":"1", "lastEapExcerDate":"2024-04-05T12:00:00.000Z", "dataUpdated":"2025-03-17T12:00:00.000Z", "usaceDistrict":"New England District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"010801", "doi_region":null, "doi_region_name":"North Atlantic-Appalachian", "doi_region_number":1 }, "id":8124021, "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/8124021?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/8124021?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/8124021?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }