Interactive Mapping Tools

As of 06/27/2019

Model and Map Management (M3) System

The Harris County Flood Control District’s Model and Map Management (M3) System is an interactive tool designed to manage changes to the Federal Emergency Management Agency’s (FEMA) effective floodplain models for Harris County. The goal of the M3 System is to distribute FEMA effective models to the general public, track ongoing changes to the models resulting from development projects, and facilitate communication between FEMA, Harris County Flood Control District, Local Floodplain Administrators, and the community. 

> View the Model and Map Management System


  1. The hydrologic (HEC-HMS) and hydraulic (HEC-RAS) models on the DVD titled "FEMA Revised Preliminary Flood Insurance Rate Maps" are no longer valid, and all FEMA effective models for Harris County are available through the M3 system.
  2. All FEMA submittals for development projects tracked by the M3 System must comply with the HCFCD Hydrologic and Hydraulic Modeling and Management Standards. 
  3. The official model software versions are HEC-HMS 3.3.0 and HEC-RAS 3.0.1. The use of different software versions must be pre-approved by the Harris County Flood Control District.
  4. For general guidance regarding hydrologic and hydraulic methodologies utilized in Harris County please download the HCFCD Hydrology and Hydraulics Guidance Manual.

Countywide FEMA Mapping Layers (Updated November 2016)
> FEMA Modeled Streams
> HCFCD H&H Modeling Standards
> HCFCD Hydrologic & Hydraulic Guidance Manual
> GIS Standards Document
> GIS for FEMA Submittals
> HEC-HMS 3.3.0
> HEC-RAS 3.0.1
> HEC-RAS 3.0.1 for Windows 7
> Annotated FIRM MXD Templates