Project Spotlight

Nassau County Westside Regional Park – Drawdown Analysis

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The subject project is located within the northwest quadrant of the intersection of US Highway 1 and Pratt Siding Road south, in the Town of Hilliard, in Nassau County, Florida. This project included gathering site and subsurface information to evaluate the subsurface conditions in the area of the proposed stormwater management ponds and use that information to estimate possible post-construction groundwater drawdown effects on the wetlands located immediately adjacent to the proposed ponds. To explore subsurface conditions Six Standard Penetration Test borings were drilled to a depth of 26 feet below the existing ground surface and to estimate the normal seasonal low water level in the wetland areas adjacent to the proposed ponds, ten auger borings were performed within the wetland areas at the stie. Nine field permeability tests were also performed immediately adjacent to the SPT boring locations. Quantitative laboratory testing was performed on selected samples of the soils encountered during the field exploration to better define their composition and to provide data for correlation to their anticipated strength and compressibility characteristics. The laboratory testing determined the percent passing the US. No 200 sieve (percent fines) and natural moisture contents of selected soil samples.