Much of the user’s manual text for Version 4 has been adapted from a computerized edition of the Version 3 manuals prepared by Dr. Brazauskas of Metcalf and Eddy, Inc., another one of the original three developers. The Fortran-77 code for Version 4 of SWMM is based on a microcomputer version prepared by Mr. Aldrich of Camp, Dresser and McKee, Inc., one of the three original SWMM developers, have given generously of their time to enhance Extran and to provide useful suggestions for improvements of Extran and the rest of the SWMM model. The Extran Block is one of the most valuable and widely-used components of SWMM.
Omission of these names from the current list of authors does not diminish our gratitude for current and past efforts in developing the model. James P.Heaney has served staunchly as colleague, critic, and pioneer of new ideas. Cunningham and Gagliardo developed the new subsurface routing routine in the Runoff Block. This users manual, however, is based upon earlier versions to which the following persons contributed significant authorship while at the University of Florida: Mr. Too many individuals have contributed to specific improvements to list here. Barnwell have also managed the Storm and Water Quality Model Users Group (formerly the SWMM Users Group), a source of invaluable feedback from model users, including a large contingent from Canada and abroad. Over the many intervening years many individuals have contributed to its improvement, notably EPA colleagues Mr. Maintenance and updating of the EPA SWMM has been continuous since its A note from the past, the SWMM3 and SWMM4 Acknowledgments from their respective manuals for the sake of posterity and in thanks for all of their past efforts.