{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -71.65931, 43.46912 ] }, "properties":{ "provider":"NAE", "code":"FFD", "slug":"ffd", "elevation":299.87, "horizontal_datum":"WGS84", "vertical_datum":"NGVD29", "state":"NH", "kind":"PROJECT", "nearest_city":"Laconia", "public_name":"Franklin Falls Dam", "location_code":8065021, "nsid":null, "aliases":{ "NIDID":"NH00003", "CWMS Legacy Naming":"FFD", "CWMS Standard Naming":"FFD" }, "timeseries":[ { "tsid":"FFD.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":410.38, "delta24h":null, "sort_order":7, "results":null }, { "tsid":"FFD.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":0.98, "delta24h":null, "sort_order":11, "results":null }, { "tsid":"FFD.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":345.22, "delta24h":null, "sort_order":6, "results":null }, { "tsid":"FFD.Elev-Pool.Inst.15Minutes.0.DCP-rev", "label":"Elevation", "base_parameter":"Elev", "parameter":"Elev-Pool", "unit":"ft", "unit_long_name":"Feet", "latest_time":"2026-08-25T21:30:00Z", "latest_value":306.87, "delta24h":null, "sort_order":1, "results":null }, { "tsid":"FFD.Precip.Inst.15Minutes.0.DCP-rev", "label":"Precipitation", "base_parameter":"Precip", "parameter":"Precip", "unit":"in", "unit_long_name":"Inches", "latest_time":"2026-08-25T22:00:00Z", "latest_value":33.73, "delta24h":null, "sort_order":16, "results":null } ], "name":"Franklin Falls Dam", "hasResopsAverages":"true", "nidId":"NH00003", "nidid":"", "levels":[ { "slug":"elev.bottom of normal", "label":"Bottom of Normal", "parameter":"Elev-Pool", "base_parameter":"Elev", "tsid":"FFD.Elev-Pool.Inst.0.Bottom of Normal", "latest_value":300, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.streambed", "label":"Streambed", "parameter":"Elev-Pool", "base_parameter":"Elev", "tsid":"FFD.Elev-Pool.Inst.0.Streambed", "latest_value":300, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of dam", "label":"Top of Dam", "parameter":"Elev-Pool", "base_parameter":"Elev", "tsid":"FFD.Elev-Pool.Inst.0.Top of Dam", "latest_value":416, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of flood", "label":"Top of Flood", "parameter":"Elev-Pool", "base_parameter":"Elev", "tsid":"FFD.Elev-Pool.Inst.0.Top of Flood", "latest_value":389, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"elev.top of normal", "label":"Top of Normal", "parameter":"Elev-Pool", "base_parameter":"Elev", "tsid":"FFD.Elev-Pool.Inst.0.Top of Normal", "latest_value":307, "units":"ft", "units_long_name":"Feet", "type":"CONSTANT" }, { "slug":"stor.bottom of normal", "label":"Bottom of Normal", "parameter":"Stor", "base_parameter":"Stor", "tsid":"FFD.Stor.Inst.0.Bottom of Normal", "latest_value":0.1, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.streambed", "label":"Streambed", "parameter":"Stor", "base_parameter":"Stor", "tsid":"FFD.Stor.Inst.0.Streambed", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"FFD.Stor.Inst.0.Top of Flood", "latest_value":150600, "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":"FFD.Stor.Inst.0.Top of Normal", "latest_value":1, "units":"ac-ft", "units_long_name":"Acre-feet", "type":"CONSTANT" } ], "id":550189, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":116, "damLength":1740, "distance":null, "drainageArea":1000, "eapId":1, "dsacAssignedDate":"2025-05-09T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2024-12-20T12:00:00.000Z", "eapLastRevDate":"2022-09-01T12:00:00.000Z", "enforcementAuthorityId":1, "federalId":"NH00003", "oldFederalId":"NH00003", "hazardId":4, "hydraulicHeight":112, "inspectionAuthorityId":1, "inspectionDate":"2024-06-18T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":1, "latitude":43.4689478220001, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-71.659306638, "maxDischarge":205000, "maxStorage":222000, "nidHeight":116, "nidStorage":222000, "normalStorage":3000, "numberOfLocks":0, "operationalStatusDate":"2015-06-15T12:00:00.000Z", "operationalStatusId":1, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":1, "politicalPartyId":null, "privateDamId":null, "projectDescription":"The U.S. Army Corps of Engineers (USACE) operates and maintains more than 700 dams across the United States. A dam is an earthen embankment and/or solid concrete structure that is built across a river, stream, or other waterway to temporarily hold back and store water that would otherwise flow downstream. More detail related to this specific dam will be added at a future time.", "riskCharSummary":"Dams do not eliminate all risk of flooding. USACE works to address all types of flood risk associated with the dam. Dams have limited capacity to store water. Water may be released through the dam to manage water levels up or downstream or to relieve pressure on the dam to maintain its structural integrity. Severe weather events that bring inconsistent or larger amounts of water into the system can also lead to dam releases or in some cases overwhelm and lead to issues occurring at a dam. \n\nAlthough Franklin Falls Dam educes the risk of flooding to downstream communities, the dam does not eliminate the risk of flooding. Franklin Falls Dam is designed to manage peak flooding levels downstream without risking the structural integrity of the dam. The most likely scenario that could result in downstream flooding is high volume releases from Franklin Falls Dam through the ungated spillway during high water events. This type of water release occurs when the reservoir's flood storage capacity is exceeded and excess water flows through the spillway. Water moving 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 four-story building. While weather can be unpredictable, this type of event can often be predicted 1-2 days before flood waters would impact downstream communities. USACE will engage state emergency managers when such an event is forecasted and support actions to get people to safety.\n\nUSACE completed a risk assessment in 2024 and classified the risks associated with the Franklin Falls Dam as low. This classification is based on the large population that lives immediately downstream of the dam in Franklin, Concord, and Manchester, NH and Lowell, MA, as well as smaller communities along the Merrimack River. Three unlikely, but more devastating scenarios that would produce significant downstream flooding are breach of the dam due to water flowing over the top of the dam; spillway erosion leading to breach of the dam; or embankment erosion leading to breach. In the case of an extremely rare and large rain event, water could potentially flow over the top of the dam, which could cause erosion of the earthen embankment, and breach of the dam. 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. Last, internal erosion of the embankment could create a flow path through the dam, which would eventually allow the crest to collapse. In these scenarios, Franklin, Concord, and Manchester, NH and Lowell, MA, along with smaller communities along the river, would be the most impacted. Downstream flooding in Franklin would occur less than an hour after of breach and the rapidly moving water could be as deep as 43 feet, destroying buildings and critical infrastructure. In addition, some evacuation routes would be under water, increasing evacuation distances.", "riskManagementMeasures":"USACE manages dam-related flood risks by continually monitoring the condition and health of the dam, prioritizing activities that will most impact the risks, and engaging upstream and downstream emergency managers and members of the public to raise awareness of the dam and support actions to prepare and be ready to respond in the case of a dam-related emergency. USACE works closely with local emergency managers to share what is known about the dam and support the development of local emergency and evacuation plans. USACE regularly updates the emergency action plan for the dam. Regular maintenance and repairs are performed as needed to keep the dam functioning properly. \n\nFranklin Falls Dam is operated in conjunction with Blackwater Dam, and is staffed full time. During high pools, Franklin Falls Dam is inspected on a daily basis. When the pool continues to rise, engineers conduct a site visit to evaluate dam performance. Geotechnical instrumentation data is reviewed regularly during normal pools and more frequently during high pools.", "riverName":"PEMIGEWASSET RIVER", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":546, "stateFedId":"NH00003", "stateRegulatoryAgency":"NH DES", "stateRegulatedId":1, "structuralHeight":116, "submitDate":"2023-02-16T17:25:37.897Z", "surfaceArea":440, "volume":3070000, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1943, "congDist":"Congressional District 02, New Hampshire", "city":"FRANKLIN", "county":"Merrimack", "aiannh":null, "websiteUrl":"https://www.nae.usace.army.mil/Missions/Civil-Works/Flood-Risk-Management/New-Hampshire/Franklin-Falls/", "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":"Dry Reservoir", "ownerNames":"USACE - New England District", "ownerTypeIds":"3", "primaryDamTypeId":5, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9", "dsacId":4, "femaRegion":"1", "lastEapExcerDate":"2024-09-05T12:00:00.000Z", "dataUpdated":"2025-05-13T12:00:00.000Z", "usaceDistrict":"New England District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"010700", "doi_region":null, "doi_region_name":"North Atlantic-Appalachian", "doi_region_number":1, "thirtyYearAverage":3.1492, "tenthPercentile":2.4178, "ninetiethPercentile":3.7744 }, "id":8065021, "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/8065021?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/8065021?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/8065021?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }