According to the US Department of Agriculture’s Weather Bureau the heavy rains started on April 28th, 1932 in the Eastern portions of the District of Columbia and in Maryland. The rain caused several small streams to overflow and claimed two lives.
The report claimed that the total rainfall was around 1.4 inches, but in areas like Anacostia, Congress Heights and Twining City the rainfall approached 4 inches. Although the report does indicate that there was probably more rain fall in areas where there were no weather gauges present.
Read the article covering the flood at University of Delaware