Water Quality Models and Tools - DFLOW

DFLOW 3.1 (released March 2006) is a Windows-based tool developed to estimate user selected design stream flows for low flow analysis and water quality standards. This latest version can be readily used by regulators in state and EPA regional offices, modelers, or anyone else interested in calculating design flow statistics. DFLOW inputs daily stream flow records (such as those records from the systematic data collection program maintained by the USGS) and calculates user-specified biologically-based design flows, hydrologically-based design flows, harmonic, and percentile flows. DFLOW can simultaneously determine and compare various design flow statistics for numerous water bodies.

Download DFLOW 3.1 (27 December 2006) (ZIP) (4.7 MB, about Zip files)  containing:

• DFlow31b-setup.exe—an installation and update file for the DFLOW 3.1 software
• USGSFlow1.8.exe—an installation file for a flow download tool developed for BASINS that will automatically download the data for all USGS gauging stations in a state, 2-digit HUC, or 8 digit HUC.
• Several sample stream flow data files.

This Web site offers the following resources for anyone interested in the DFLOW and/or low flow water quality standards and statistics:

• Basic Information provides information on the development and uses of DFLOW and the differences between DFLOW 3.1 and earlier versions.
• Flow 101 provides background information on low flows, droughts, water quality standards, hydrologically-based design flows (e.g., 7Q10), biologically-based design flows (e.g., 4B3), and other related topics.
• Applications illustrate how DFLOW was used to analyze design flow statistics in a case study.
• Technical Support answers frequently asked questions about using DFLOW.