Engineering Tools

HEC-1 HC Card Cumulative Drainage Area Calculation Tool


The software is designed to automatically calculate the drainage area at each hydrologic concentration point in an existing HEC-1 input file. View more information and download the tool.

FLO-2D Viewer



Open the Viewer
This map is intended for use by experienced engineers as a design aid for preparing site drainage and grading plans, and for establishing building lowest floor elevations for new structures. Users are strongly encouraged to consult with District staff prior to applying this information for the first time to obtain a clear understanding of the basis for the information and for guidance in its application. The map, however, is not an official document that may be used for floodplain determination.

This map is designed to assist in obtaining the results of hydrologic and hydraulic modeling for a portion of the Rio Verde Area Drainage Master Plan (ADMP). A 25.1-square-mile portion of the 40-square-mile ADMP study area was analyzed using a grid-based 2-dimensional computer model. Information is available for each 25-foot by 25-foot square grid for the entire 25.1-square-mile detailed study area. The information available is an estimate of the 100-year 24-hour storm peak discharge in cubic feet per second, the dominate direction of that discharge, and the resulting peak water surface elevation on the NAVD 1988 vertical datum. The results are the average for each grid element. The preliminary floodplain boundaries also shown on the map are based on this data.

NSTPS Tool 1.0.0


Released on June 17, 2013 as a Beta version. NSTPS Tool 1.0.0 is a software package designed to automatically update the NSTPS parameter (HEC-1 RS card's first field) for flow routing in channels in an HEC-1 input file.

Drainage Design Management System


The District offers the latest version (Version 5.3.0 - April 12, 2016), as well as prior versions and upgrade versions of the DDMSW.

Manuals & Additional Resources


Search through a variety of additional resources and manuals made available online on our Flood Control District Library Catalog page.

Find our Best Management Practices (BMP files from Drainage Design Manual, Erosion Control).