Title | Storm flow from first-flush precipitation in stormwater design |
Publication Type | Journal Article |
Year of Publication | 2004 |
Authors | Ahlfeld D. P., Minihane M |
Journal | Journal of Irrigation and Drainage Engineering |
Volume | 130 |
Issue | 4 |
Start Page | 269 |
Pagination | 269-276 |
Date Published | 08/2004 |
Keywords | precipitation, Storms, water, Water treatment |
Abstract | Regulations for mitigating nonpoint source pollution from urban areas often include a requirement for treatment of a first-flush depth of stormwater. When the stormwater treatment technology requires specification of a design flow rate, the first-flush depth must be related to a first-flush flow rate. This paper describes a methodology to determine the relation between accumulated storm depth and corresponding flow to a treatment device for small, urban watersheds. The approach uses the rational method under the assumption that the time-of-concentration is small. Intensity–frequency relations, expressed in the form of return periods and associated intensities, were determined using a partial duration frequency analysis of regionalized precipitation data. The results of the method can be used to determine the flow rate to a treatment device that will meet a specified return period for a first-flush depth. The method is demonstrated using 13 years of 15-min data from seven Massachusetts precipitation stations. |
DOI | 10.1061/(ASCE)0733-9437(2004)130:4(269) |