Community Pier Development
Vessel Scour Analyses and Capping Plan
The lakefront property boundary of a new residential community is located approximately 600 ft down the shoreline from a USEPA Superfund Site at a former creosote manufacturing facility. Our client, a real estate development company, proposed to construct a community pier to provide lake access and private moorage for approximately one hundred (100) property owners within the new development. To address the concerns of the USEPA and State agencies regarding lakebed sediment stability adjacent to but not part of the Superfund site, Lally Consulting LLC was contracted to conduct particle stability analyses under potential vessel-induced scour sources in order to permit construction of the new pier facility.
Lally LLC acquired a bathymetric survey of the site, determined typical and worst-case design vessel types, operating parameters, and analyzed propeller-induced scour using numerical modeling methods, as well as other erosion forces, to determine stable particle sizes in the vicinity of the new pier facility. Results of the analyses were summarized in a sediment transport analysis report, along with recommended mitigation actions, including an engineered cap plan designed using habitat-conducive components to contend with highest velocities, an aids-to-navigation plan, and construction best management practices (BMPs) to limit scour potential at and adjacent to the new community pier.
The comments received from the USEPA other stakeholders were positive, and, with slight refinement of the cap gradation to improve ecological function of the site for salmonids, the new pier construction was permitted to proceed.
Services Provided
Propeller Wash Modeling
Particle Stability Analyses
Novel Presentation Graphics
Nature-based Cap Design and Management Plan
Construction Best Management Practices
Aids-to-Navigation Plan
Cost Estimates
Location
Pacific Northwest
Period
2010 – 2012