Evaluation of Infiltration Basin Performance on Coarse Soils: Fid-Bau Portal

Evaluation of Infiltration Basin Performance on Coarse Soils

Dukes, Michael D

AbstractInfiltration basins are commonly utilized to reduce or eliminate stormwater runoff and are commonly located on coarse soils due to relatively high infiltration rates. Forty infiltration basins in Florida were included in this field study to evaluate whether basin infiltration rates varied significantly from their designed infiltration rates. Basins were located among Leon, Alachua, and Marion counties in Florida, while watershed land uses were equally divided between Florida Department of Transportation and residential developments. Generally, six test sites within each basin were selected for infiltration rate measurement by double-ring infiltrometer (DRI). Also, a soil boring was collected from each test site for analyses, including soil texture, bulk density, and organic matter content. Infiltration rates were log-transformed and statistical analysis was used to determine if DRI measurements were significantly different from design rates. Basin soil textures were well distributed between sand, loamy sand, sandy loam, and sandy clay loam. Most (91%) bulk densities ranged between 1.30 and 1.80 g/cm3 and organic matter percentages ranged from 0.1 to 48.5%, with 49% of soils having less than 3.0% organic matter. Nearly all bulk densities were not limiting to vegetation growth for the respective soil texture. Based on DRI rates, 16 (40%) basins had rates significantly less than their designed rates, 10 (25%) had rates equal to their designed rates, and 14 (35%) basins had rates significantly greater than their designed rates. Basins with coarser soils were also more likely to have DRI rates greater than designs. In addition, a higher proportion of basins located within Florida Department of Transportation watersheds had DRI rates greater than or equal to design rates, which may be related to vegetation size and diversity.