According to records, a major flood occurs somewhere within Harris County at the rate of one nearly every two years, with event records beginning shortly after Houston’s founding.

Today, the Harris County Flood Control District (HCFCD) is proactively planning for such events, using Arc Hydro as the framework for its current watershed planning initiative. Recently, the District began to assess current floodplain conditions within the county’s 22 watersheds, and to examine controls that could adequately manage the floodplain while addressing the development needs in the Houston area.

Each watershed will have an environmental inventory performed and each natural, cultural, and physical resource deemed necessary to the evaluation of potential project alternatives will be cataloged and quantified in a geographic information system (GIS) called a watershed environmental baseline (WEB) map. The HCFCD is using several consultants to complete the 22 WEB maps and – to ensure that every consulting team populates the geodatabase consistently – PBS&J’s Information Solutions division has been asked to design the standard GIS data model.

Using a customized version of Arc Hydro, the data model that PBS&J is creating (HCHydro) incorporates existing HCFCD database design and legacy naming conventions into the Arc Hydro framework. The model also provides a consistent template that standardizes geodatabase structure including feature datasets, feature classes, domain tables, field names, types, and sizes.

The HCHydro data model is being developed in phases to support each level of the watershed planning effort. Many Arc Hydro and HEC-GeoRAS tools are being used to analyze, populate, update, and manipulate HCHydro. Furthermore, custom tools are being designed to automate portions of the production procedures to support the HCHydro design and planning efforts.