One of the things that go into the beginning design phases of any field project is soil testing. A series of soil tests are pertinent to evaluate the existing conditions and type of soil on which a new field will be constructed. Soils heavy in fine particulates such as silt and clay will likely compact easily and inhibit free drainage, while coarser material such as sand works the opposite but has less stability. The type of clay is also important as there are many types and their stability varies when introduced to water. Infiltration rates should be tested under normal conditions, before compaction, to understand how the field will need to be designed for optimal performance. Low infiltration rates will dictate that the bulk of drainage is handled (1) at the surface by crowning or sloping the field and allowing water to move horizontally toward the sidelines or (2) below the surface by installing larger drainage systems that can contain and store larger volumes of water and slowly release it over time. High infiltration rates reveal that water can easily move vertically through the soil profile and may signal the need for a subsurface drainage system that slows down the discharge rate. The information gathered in these initial soil tests determines the stormwater holding capacity and downstream runoff calculations. It’s also critical to meet with local permitting authorities and Water Management Districts to determine the allowable rates by the local jurisdiction. A of this information is required to complete the design of a drainage system.