1240815StormWaterManagementReportrcd 3 12 2026

POROUS PAVERS MOUNDING CALCULATIONS Input Values 2.90 R Recharge rate (permeability rate) (in/hr) Specific yield, Sy (dimensionless) 0.150 Sy default value is 0.15; max value is 0.2 provided that a lab test data is submitted Horizontal hydraulic conductivity (in/hr) 2.90 Kh Kh = 5xRecharge Rate (R) in the costal plan; Kh=R outside the coastal plan 30.000 x 1/2 length of basin (x direction, in feet) 16.000 y 1/2 width of basin (y direction, in feet) 2.25 t Duration of infiltration period (hours) 10.00 hi(0) Initial thickness of saturated zone (feet) 13.680 h(max) Maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 3.680 Δh(max) Maximum groundwater mounding (beneath center of basin at end of infiltration period) Distance from Ground-water center of basin in x Mounding, in feet direction, in feet 3.680 0 3.667 10 Re-Calculate Now 3.447 20 1.850 30 Groundwater Mounding, in feet 0.200 40 4.000 0.010 50 0.001 60 3.500 0.001 70 3.000 0.001 80 2.500 0.001 90 2.000 1.500 1.000 0.500 0.000 0 10 20 30 40 50 60 70 80 90 100 -0.500 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin

0 90 100 -0.500 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. 146 150