In 1990, the Urban Drainage and Flood Control District (UD and FCD) joined with several cities and counties in the Denver metropolitan area, to support the University of Colorado at Denver to develop practical computerized methodology for street storm water collection system design. This effort resulted in the development of a computer model called UDINLET which was written for street hydraulic capacity and inlet design. This model was tested for various types of street inlet and found to have good agreements to published data. When the street cross sectional geometries are known, UDINLET model predicts the flow capacities at various depths of one inch increments. When a design discharge is given, the program computes the water spread on the street and depth at the gutter. To size a street inlet specified by the engineer, the program starts with the prediction of the design discharge which consists of local basin contribution and carryover flow from the upstream inlets. The next step determines the ideal and allowable street capacity based on the maximum spread and curb height. Then the inlet is sized. Types of inlets considered in UDINLET include grate, curb-opening, combination of grate and curb opening, and slot drain. Inlets can be placed on a sump or on a grade. Inlet interception capacity and the amount of the carryover flow are determined with the consideration of the user-specified clogging factor. From the Table of Contents: Introduction Street Capacity and Inlet Design procedures Curb and Gutter Types Determination of Design Storm Event Determination of Design Discharge Street hydraulics Types of Inlets Inlet Hydraulics Carryover Flow Computer Hardware Requirements Installation of UDINLET How to Run UDINLET Case Studies. 1. Street ideal and allowable hydraulic capacities under a minor as well as a major storm event; 2. Design peak runoff by the Rational method with or without a carryover flow; 3. Inlet selection among grate, curb opening, combination and slotted drain; 4. Inlet sizing according to street hydraulics, gutter geometry, depression, curb height, allowable water spread, sump depth, and public safety, and; 5. Inlet ideal and actual interception and carryover flow with the consideration of a clogging factor.