Caption title. At head of title: Project summary. Distributed to depository libraries in microfiche. "Sept. 1984." "EPA/600-S2-84-109a & b."

" A description is given of the third update of a user's manual for the U.S. Environmental Protection Agency (EPA) Storm Water Management Model (SWMM). The manual should be used with Addendum I to run the Extran block (detailed hydrologic flow routing). The SWMM is a comprehensive mathematical model developed for both continuous and single event simulation of urban runoff quantity and quality in storm and combined sewer systems. All aspects of the urban hydrologic and quality cycles are simulated, including surface runoff, transport through the drainage network, storage and treatment, and receiving water effects. (The latter component is currently under revision by EPA.) Detailed descriptions are provided in the User's Manual for all blocks except the Receiving Water Block. Blocks include Runoff, Transport, Storage/ Treatment, Combine, Statistics, and Graph. The latter three are service blocks, and the first three are the principal computation blocks. In addition, extensive documentation of new procedures is provided in the text and in several appendices."