Lancaster Culverts

JM Davidson Engineering, D.P.C. (JMD) was subcontracted by DiDonato Associates to assist with the hydraulic analysis and environmental permitting for the rehabilitation of multiple culverts in the Town of Lancaster.  One culvert is located on Warner Road, carrying an unnamed tributary to Scajaquada Creek.  The culvert under the roadway is part of a Bridge NY application prepared by DiDonato Associates for the Town.  JMD assisted with performing a hydraulic analysis to estimate the existing capacity of the culvert and to determine the effects upstream if the culvert were either lined or replaced. The analysis and additional environmental screening were used to support the Bridge NY application. 

The remaining culverts were all part of a series of culverts on the North Branch of Slate Bottom Creek.  The culverts were installed around 1990 when the subdivision was first developed.  The three crossings analyzed each contain three roughly 60-dia. CMP pipe arches in each group.  JMD was responsible for performing the hydraulic analysis, including a FEMA no-rise analysis, in support of the culvert rehabilitation project.  JMD also conducted the wetland delineation, SHPO coordination, environmental screenings, and ultimately the permit applications for the proposed work. 

The work performed includes:

• Conducted a wetland delineation at the various culvert locations.
• Conducted a site visit to obtain field measurements of the culverts and hydraulic parameters included in the model.
• Prepared a HEC-RAS model of the existing and proposed culverts and performed a no-rise analysis since this project is located within a FEMA floodplain with a floodway.
• Conducted an environmental screening for the project, including coordination with SHPO, USFWS, NYSDEC Natural Heritage Program, wetland delineation, and other pertinent social and economic impacts.
• Prepared a hydraulic summary memo and environmental screening text for the Bridge NY application.
• Prepared a No-Rise Certification for the Floodplain Development Permit.
• Prepared and coordinated with USACE and NYSDEC for the necessary Section 404 Nationwide Permit and Section 401 Water Quality Certification.