* Step 1: Based on the median measured infiltration rate of the native soil at the estimated location and bottom elevation of the practice, or estimated from the median grain-size distribution results, decide if an underdrain will be included in the design. See [[Design infiltration rate]] for guidance on field tests, methods and number of test locations and tests (i.e. measurements) to be performed.<br> | * Step 1: Based on the median measured infiltration rate of the native soil at the estimated location and bottom elevation of the practice, or estimated from the median grain-size distribution results, decide if an underdrain will be included in the design. See [[Design infiltration rate]] for guidance on field tests, methods and number of test locations and tests (i.e. measurements) to be performed.<br> |