Overview of Artifical Recharge by Surface Infiltration

As part of a project to predict the infiltration rate at a particular storm water collection basin in California, we conducted analyses based on rather extensive site specific field and laboratory measurements. To evaluate the reasonableness of our findings, we compiled reported long-term infiltration rates for other locations within the basin as well as at other basins throughout the United States. A cumulative probability plot reveals a surprisingly narrow spread in field infiltration, with an expected value on the order of 1 to 3 feet per day.  This finding is explained by basic principles governing infiltration, the development of clogging layers and soil hydraulic properties. The analysis leads to general expectations for infiltration rate and potentially useful rules of thumb as well as implications for basin design and management.