Illinois least-cost sewer system design model: ILSD-1 & 2 user’s guide

ILSD models are sewer system models for least-cost optimal design of the entire system. ILSD-1 designs for a specified layout the size and slope of the sewers with or without detention storages with user supplied rainfall and/or inlet hydrographs. ILSD-2 is similar to ILSD-1 but also with risk consideration; i.e., with the risk damage cost included in the optimization procedure and a risk equation supplied by the user. The user may choose either ILSD-1 or 2 as he (she) wishes and according to the available data. This user's guide provides the necessary information to use the computer program. Data preparation for various options to fit different engineering situations is presented.U.S. Department of the InteriorU.S. Geological SurveyOpe