The City of Scranton is seeking proposals from qualified firms to provide photogrammetric and Geographic Information Systems (GIS) services to support the development of a Regional Stormwater Authority for eight (8) municipalities in Lackawanna County, Pennsylvania. This work will include high resolution aerial imagery capture and feature extraction that will produce an impervious area (IA) GIS dataset for the study region. The IA dataset will be processed along with property parcel features to calculate IA square footage. As the mapping specifications listed below indicate, the goal is to develop a highly accurate and defendable GIS dataset that will become the basis for stormwater authority billing. Bidders will have demonstrated experience in GIS feature extraction for regional projects of similar size ( > 65 square miles) with preference to firms with project history related to IA, stormwater, and/or fee development. A. Study Area: The project area covers the following municipalities in Lackawanna County: Taylor Borough, Borough of Dickson City, Old Forge, South Abington, Dunmore, Moosic, Clark Summit, and City of Scranton. According to County GIS parcel data, there are approximately 50,400 properties in the study area of which approximately 44,400 (88%) are residential. B. Project Specifications: The City of Scranton is interested in receiving proposals to complete the work scope with the following technical specifications. We understand that different approaches can be taken to achieve project goals, such as traditional photogrammetry (hand-extraction) or machine learning methods. Bidders should explain how the proposed methodology will meet the accuracy needs of the final data product and describe any limitations. The bidder will acquire/produce aerial imagery according to the following: • Orthophotography derived from digital imagery at a resolution of 0.5’ (6”) ground pixel or better • Meet or exceed American Society of Photogrammetry & Remote Sensing (ASPRS) Class 1 accuracy standard for 1”=50’ scale mapping • Three-band (RGB) natural color ortho imagery delivered in MrSID format • Capture / represent leaf-off conditions in the fall/winter of 2024 The bidder will extract impervious surface areas from the digital imagery according to the following: • All parcels in the study area will be reviewed for IA; we will provide a parcel dataset to define the coverage area at project kick-off • IA types will include: ▪ Pavement, asphalt, and concrete ▪ Packed gravel, crushed stone, compacted dirt (on parking, storage, and travel ways) ▪ Rooflines of walled, fixed structures • Public roadways outside of property parcels will not be captured; private roads located within parcel boundaries will be included • Ground features larger than 10’x10’ will be captured • Extracted features and feature edges are expected to be fully represented even when obstructions (tree canopy) are present; this includes distinctions between building & pavement/concrete edges, as well as distinctions between gravel, grass, and paved surfaces; defined feature edges with little omission is critical to obtaining accurate IA calculations for all parcels of varying sizes • IA should be categorized in the GIS attribute table GIS by at least three (3) feature types – building, roadway, and “other” • Before the IA extraction process, the bidder will meet with the project team to review the specific types of IA to be extracted to suit the needs of the stormwater authority program. • Deliverable format will be an ESRI geodatabase file in the project coordinate system – NAD83 PA Stateplane North, US Survey Feet. C. Schedule: Aerial imagery will be captured in October / November of 2024 with GIS deliverables provided by April 2025. Bidders should provide a reasonable schedule for project delivery including contingencies. D. RFP Response: Interested bidders shall submit a proposal and include the following: • Project understanding and suggested technical approach • Statement of accuracy of proposed imagery and GIS deliverables • Examples of past projects similar in scope, size and client type; as stated, experience in IA feature extraction and regional stormwater projects is preferred • Estimated lump sum pricing, including any subscription fees for imagery • Proposed project schedule
