{ "bbox":null, "type":"Feature", "geometry":{ "bbox":null, "type":"Point", "coordinates":[ -79.90026, 41.9205 ] }, "properties":{ "provider":"LRP", "code":"UnionCity", "slug":"unioncity", "elevation":0.0, "horizontal_datum":"WGS84", "vertical_datum":"NAVD88", "state":"PA", "kind":"PROJECT", "nearest_city":"Erie", "public_name":"Union City Dam", "location_code":16806111, "nsid":null, "aliases":{ "NIDID":"PA00103" }, "timeseries":[ { "tsid":"UnionCity-Lake.Precip-Inc.Total.1Hour.1Hour.OBS", "label":"Precipitation", "base_parameter":"Precip", "parameter":"Precip-Inc", "unit":"in", "unit_long_name":"Inches", "latest_time":"2026-04-14T16:00:00Z", "latest_value":0.0, "delta24h":null, "sort_order":16, "results":null }, { "tsid":"UnionCity-Lake.Stor.Inst.1Hour.0.OBS", "label":"Conservation Storage", "base_parameter":"Stor", "parameter":"Stor", "unit":"ac-ft", "unit_long_name":"Acre-feet", "latest_time":"2026-04-14T21:00:00Z", "latest_value":4757.69, "delta24h":null, "sort_order":13, 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"latest_value":1277.7, "units":"ft", "units_long_name":"Feet" }, { "slug":"elev.top of inactive", "label":"Top of Inactive", "parameter":"Elev", "base_parameter":"Elev", "tsid":"UnionCity.Elev.Inst.0.Top of Inactive", "latest_value":1209.7, "units":"ft", "units_long_name":"Feet" }, { "slug":"stor.minimum", "label":"Minimum", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Minimum", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.streambed", "label":"Streambed", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Streambed", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of conservation", "label":"Top of Conservation", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Top of Conservation", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of dam", "label":"Top of Dam", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Top of Dam", "latest_value":113056, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of flood", "label":"Top of Flood", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Top of Flood", "latest_value":47652, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of full", "label":"Top of Full", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Top of Full", "latest_value":47652, "units":"ac-ft", "units_long_name":"Acre-feet" }, { "slug":"stor.top of inactive", "label":"Top of Inactive", "parameter":"Stor", "base_parameter":"Stor", "tsid":"UnionCity.Stor.Inst.0.Top of Inactive", "latest_value":0, "units":"ac-ft", "units_long_name":"Acre-feet" } ], "id":550091, "associatedStructuresCount":0, "conditionAssessDate":null, "conditionAssessDetail":null, "conditionAssessId":6, "damHeight":null, "damLength":1420, "distance":null, "drainageArea":222, "eapId":1, "dsacAssignedDate":"2020-07-21T12:00:00.000Z", "eapMeetsGuidelinesId":1, "emergencyContactsUpdated":"2024-10-25T12:00:00.000Z", "eapLastRevDate":"2017-05-05T12:00:00.000Z", "enforcementAuthorityId":0, "federalId":"PA00103", "oldFederalId":"PA00103", "hazardId":4, "hydraulicHeight":83, "inspectionAuthorityId":0, "inspectionDate":"2024-06-28T12:00:00.000Z", "inspectionFrequency":5, "jurisdictionAuthorityId":0, "latitude":41.9204990110001, "lengthOfLocks":0, "secondaryLengthOfLocks":null, "longitude":-79.900351499, "maxDischarge":64000, "maxStorage":94000, "nidHeight":88, "nidStorage":94000, "normalStorage":0, "numberOfLocks":0, "operationalStatusDate":"2020-07-21T12:00:00.000Z", "operationalStatusId":1, "originalDesignerName":null, "otherStructureId":null, "permittingAuthorityId":0, "politicalPartyId":null, "privateDamId":null, "projectDescription":"The U.S. Army Corps of Engineers (USACE) constructed Union City Dam across French Creek in 1970 to hold back water during flood events to reduce the risk of downstream flooding in the low-lying communities in Waterford, Cambridge Springs, Saegertown, Meadville, and additional towns along French Creek in Crawford, Erie, Venango, and Mercer County. The dam is located about 3 miles northwest of Union City, Pennsylvania and forms the Union City Reservoir. Union City Dam has reduced flood damage by more than an estimated $110 million since being commissioned. The reservoir stores rainfall and passively releases water during and after flood events to diminish potential flood damage along French Creek. Union City Dam is composed of an earthen (embankment) portion and has a maximum height of 88 feet and a length of about 1,400 feet. The dam has a system of outlets, including a concrete conduit that discharges directly downstream of the dam during periods of normal reservoir levels. There is a concrete basin on the right side of the dam that allows water into a spillway during periods of unusually high reservoir levels and around the dam to the downstream French Creek; water enters the concrete basin from the reservoir over a concrete surface called a weir. There is a narrow opening in the weir that allows water to enter the concrete basin during periods of normal, but elevated reservoir levels. Since the project began operation in 1970, the reservoir level has never risen above the top of the concrete weir and so people along French Creek downstream of Union City Dam have not experienced flooding related to full spillway flow.", "riskCharSummary":"The most recent risk assessment for Union City was completed in 2024, which characterized the risk posed by the dam as very low. The dam was well-constructed and is well-maintained. However, multiple populations live downstream of Union City Dam, including those in Waterford, Cambridge Springs, Saegertown, Meadville, and other low-lying communities along French Creek in Crawford, Erie, Venango, and Mercer County. Although the dam reduces the risk of flooding to these communities, it does not eliminate flooding. The most likely scenario resulting in downstream flooding from Union City Dam would be a high-volume release over the dam\u2019s spillway during an unusually large and intense storm event. Water released over the spillway could create conditions similar to how French Creek would behave if the dam had not been constructed. \n\nTwo less likely, but far more devastating flooding scenarios exist during extreme rainfall events. 1.) If the reservoir level rises about the crest of the embankment dam, water will flow over the downstream face of the earthen embankment, eroding the embankment, potentially leading to a breach. 2.) Water flowing over the spillway could increase water pressures beneath the spillway weir or erode the bedrock that supports the spillway weir to the extent that concrete portions of the spillway weir breaches (i.e., moves downstream and releases additional water to the downstream French Creek). Although such a precipitation event leading to a breach is extremely rare, it is a possibility.\n\nIn either scenario, a large surge of water would flow out of the reservoir, flooding downstream communities. Communities, including Waterford, that are closer to the dam, are in more immediate danger of flood and may have little advanced warning. Cities and communities further downstream of the dam, such as Cambridge Springs, Saegertown, Meadville and communities in Crawford, Venango, and Mercer County may have larger populations and possibly less awareness of the dam but will have more warning. \n\nWith either of the scenarios described above, the downstream floodwater would be swift and deep, possibly overflowing banks on French Creek, destroying buildings and infrastructure. Anyone caught unaware and/or unable to evacuate could perish. In the less likely dam breach scenario, the water depth, property damage, and lives lost would likely be far greater.", "riskManagementMeasures":"To ensure we are taking all steps to reduce the risk to the public, we will continue to work closely with state and local emergency managers, conduct emergency exercises and incorporate any new information into our emergency action plans. We will continue rigorous monitoring and surveillance of the dam and will do so more frequently during high-water events. We closely follow rainfall forecasts to determine when high-water events may occur to provide information for any necessary flood warnings. We will work with local communities to provide opportunities to engage with residents to help them understand how they can better prepare for a flood. In partnership with the US Geologic Survey and the National Weather Service, information on current lake levels at Union City Reservoir is available to the public via the internet at: \n\nhttps://waterdata.usgs.gov/monitoring-location/03021518/#dataTypeId=continuous-62615-1922206742&period=P7D&showMedian=true", "riverName":"FRENCH CREEK", "separateStructuresCount":0, "sourceAgency":"US Army Corps of Engineers", "spillwayTypeId":3, "spillwayWidth":268, "stateFedId":"PA00103", "stateRegulatoryAgency":null, "stateRegulatedId":0, "structuralHeight":88, "submitDate":"2023-02-16T17:25:40.510Z", "surfaceArea":1, "volume":1112600, "widthOfLocks":0, "secondaryWidthOfLocks":null, "yearCompleted":1971, "congDist":"Congressional District 16, Pennsylvania", "city":"UNION CITY", "county":"Erie", "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;3", "nonFederalDamOnFederalId":0, "designerNames":"CELRP", "otherNames":"Union City Lake", "ownerNames":"USACE - Pittsburgh District", "ownerTypeIds":"3", "primaryDamTypeId":8, "primaryOwnerTypeId":3, "primaryPurposeId":9, "purposeIds":"9;12;4;5", "dsacId":5, "femaRegion":"3", "lastEapExcerDate":"2025-06-10T12:00:00.000Z", "dataUpdated":"2025-06-12T12:00:00.000Z", "usaceDistrict":"Pittsburgh District", "noConsequencesId":0, "secretaryAgricultureBuiltId":null, "nrcsWatershedAuthorizationId":null, "isAssociatedStructureId":"No", "fedRegulatedId":"Yes", "inundationNidAddedId":1, "damStatusId":2, "huc06":"050100", "doi_region":null, "doi_region_name":"North Atlantic-Appalachian", "doi_region_number":1 }, "id":16806111, "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/16806111?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/16806111?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr/items/16806111?f=html" }, { "rel":"collection", "type":"application/json", "title":"USACE Access2Water API", "href":"https://api.wwdh.internetofwater.app/collections/usace-edr" } ] }