Free Software / Free Documents - As In No Cost

(that is correct - no money to pay)

If it is on this site, then there is a 99%+ probability that it is free... adware, no spyware, just free

IF you can't find something OR need assistance THEN email me AND I'll try to help

Click "HHWQ" above for full listing of 150+ completely free software applications available for download from web site main page (if you are not on the main page already)

Please spread the word by posting links to this site!


Catchment pollution calculators (NSW Stormwater Trust)

Calculate a pollutant load in kg from kg/Ha/yr export rates (spreadsheet)

Calculate a pollutant load in lbs from lbs/acre/yr export rates (spreadsheet)

Convert an event mean pollutant concentration into an export rate (spreadsheet)

Compare the cost-effectiveness of investments in alternative treatment technologies (spreadsheet)

TRAGIC++ (interactive forest stand simulation program)

I know this may seem like a lot of focus on tree stuff, but canopy effects (such as interception) can be mighty important in HHWQ modeiling/simulation.

In TRAGIC++, the development of a forest is simulated as the collective dynamics of individually growing trees, each of which competes with the others for light, space and nutrients. Interaction is possible by removing or planting single or groups of trees and by changing the environmental conditions (light an nutrients).

Simple Light Interception Model (SLIM)

Another software package useful for developing precipitation interception and canopy evapotranspiration model input parameters. If nothing else, you can make some cool images with it.

Storm Damage Assessment Protocol (i-Tree)

The i-Tree Storm Damage Assessment Protocol Utility establishes a standard method to assess widespread damage immediately after a severe storm in a simple, credible, and efficient manner. This assessment method is adaptable to various community types and sizes, and it provides information on the time and funds needed to mitigate storm damage.

I haven't used or tried this software (unlike 95% of the other stuff on the HHWQ blog site) and the the i-Tree site looks a bit tree-huggerish, but this looks like a good tool.

USFS: Forest Vegetation Simulator (FVS)

For those of you intersted in precipitation interception and canopy evapotranspiration, the Forest Vegetation Simulator (FVS) can be a useful tool for developing input parameters.

SWRC-Fit (Soil Water Retention Curve Fitting)

The soil hydraulic parameters for analyzing water movement in variably saturated soil can be determined by fittig soil hydraulic model to a soil water retention curve. SWRC-Fit performs nonlinear fitting of 5 soil hydraulic models (Brooks and Corey, van Genuchten, Kosugi, Durner, Seki) to a measured soil water retention curve.

HHWQ data tools (RIIC)

Software from Research Institute for Industrial Crops (SIPEAA Project)

WeatherFile: utility to convert weather files of different formats.

Rain: generate long-term series of precipitation values using parameters from existing daily or monthly precipitation records.

ET estimate daily and hourly values of evapotranspiration from the reference surface, according to alternative approaches.

CLIMA (under development): produce synthetic values of climate variables (precipitation, air temperature, solar radiation, vapor pressure deficit, wind speed, reference evapotranspiration) from existing daily weather data


Geographical Information System (GIS) with tools for estimation and analysis of hydrological, climatic, and geomorphological variables.

Multi-Dimensional Modeling System (USGS)

Graphical User Interface (GUI) for computational models of surface-water hydraulics. The system is both a tool and framework that provides an easy to use interface to a variety of environmental hydraulic models.

Fityk: peak fitting (curve fitting)

Nonlinear fitting of analytical functions (especially peak-shaped) to data (usually experimental data). There are also people using it to remove the baseline from data, or to display data only. Good for analysis/processing of bathymetric sounding/sonar data when setting up estuary/river models.

DESIRE: Direct Executing SImulation in REal Time

Interactive modeling, simulation of dynamic systems, immediate comparisons of live models. OPEN DESIRE is listed as free (other than shipping and handling). DESIRE/2000 is not free, but I can't discern the difference.

Open Workbench: project management software

Nice alternative to Microsoft Project. Not a hydrologic, hydraulic, or water quality software application, but - like OpenOffice - a great software application for your work. Gantt charts, process schedules, etc...

SciCraft: data analysis tool

Easy-to-use graphical user interface (GUI) for basic data analysis stuff as well as more advanced statistics, chemometrics, and "artificial intelligence"

Erosion Control Materials Design Software ECMDS - North American Green

Blatantly commercial, but free to download and use. Very useful software for design of vegetated channels, including analysis reports.


Data translation and conversion application.

3DFlow (Department of Civil Engineering at Kansas State University)

Visualization of three-dimensional groundwater flow associated with horizontal wells, partially penetrating wells and fully penetrating wells.

USGS Water Data for the Nation

* Current-conditions data transmitted from selected surface-water, ground-water, and water-quality sites
* Descriptive site information for all sites with links to all available water data for individual sites.
* Water flow and levels in streams, lakes, and springs.
* Water levels in wells.
* Chemical and physical data for streams, lakes, springs, and wells.

USGS: StreamStats

StreamStats is a Web-based tool that allows users to obtain streamflow statistics, drainage-basin characteristics, and other information for user-selected sites on streams.

MMS: Modular Modeling System

Development of the Modular Modeling System appears to be continuing, the a native Microsoft Windows version would be helpful (as opposed to a CYGWIN implementation)

USGS National Flood Frequency (NFF) Software

Excellent software for quick estimates of peak runoff

* Obtain estimates of flood frequencies for sites in rural (non-regulated) ungaged basins.
* Obtain estimates of flood frequencies for sites in urbanized basins.

Manning's Open Channel Flow Model Roughness (n values)

Verified Roughness Characteristics of Natural Channels

Descriptions of "verified" Manning's roughness coefficients for various channels with associated photographs.

A picture is worth a thousand words...

MIKE SWMM - available as freeware

DHI-WEH produces some excellent hydrology, hydraulic, and water quality software applications. Unfortunately, these are some of the most expensive such software applications available anywhere.

MIKE SWMM (from DHI-WEH) is now available free of charge to anyone who would like to use it: freeware. It is based on SWMM4.4x and does not support the latest version of SWMM (5.x).

The company is focusing development resources on MIKE URBAN, phasing out MIKE SWMM, MOUSE, and MIKE STORM.

NetSTORM: urban watershed simulations

NetSTORM is CDM's computer program for precipitation data assessment and rapid long-term urban runoff simulation.

* Storage – Treatment – Overflow Runoff Modeling
* Precipitation intensity – duration – frequency (IDF) analysis
* Time series aggregation and synthetic disaggregation
* Data conversion from various US National Weather Service formats to tabular formats
* Automated SWMM model simplification, gradually varied flow profiles, and more


Downloadable dissertations and theses

Dissertations and theses prepared by graduate students are excellent sources of information on various aspects of hydrology, hydraulics, and water quality. You can access and download electronic versions of dissertations and theses from various academic institutions.

The Networked Digital Library of Theses and Dissertations (NDLTD) is an international organization dedicated to promoting the adoption, creation, use, dissemination and preservation of electronic analogues to the traditional paper-based theses and dissertations.

Download eBook: Handbook of Soil Analysis: Mineralogical, Organic, and Inorganic Methods

Reference guide for selecting and carrying out numerous methods of soil analysis.

EPA Stormwater Guidelines for Green, Dense Redevelopment

City of Emeryville (California)

Spreadsheet Model


PFDS: Precipitation Frequency Data Server

NOAA National Weather Service - rain storm data
Intensity Duration Frequency (IDF)
Depth Duration Frequency (DDF)


EPA: Stormwater Sizing Spreadsheets

BioFiltration Swale
BioRetention Basin
Flow-through Planter Box
Lowered Planter Strip
Metered Detention

WaSim water balance model

Analysis and education tool for irrigation, drainage, infiltration, and salinity management.

Low Impact Development Center: two spreadsheets

Bioretention Cell Sizing

Tahoe Regional Planning Agency Stormwater Tools

BMP sizing worksheets

Calc Sheet General Information
Calc Sheet Instructions
Calc Sheet (Eldorado County)
Calc Sheet (Placer County)
Calc Sheet (Nevada)

Water Balance Model: Arizona Department of Environmental Quality

Blaney-Criddle Water Balance Spreadsheet

Explanation of the Blaney-Criddle Water Balance Spreadsheet

Design flood estimation

Spreadsheet implementation of the revitalised FSR/FEH rainfall runoff method (ReFH)

Models: Impacts of Land Use Change on Water Resources

L-THIA (Long-Term Hydrologic Impact Assessment): provides site-specific estimates of changes in runoff, recharge, and nonpoint source pollution resulting from past or proposed land use changes

SedSpec: assists in analyzing runoff and erosion problems on site by determining the peak rate of runoff from the area

Rain Garden Spreadsheet

Basic analysis spreadsheets with pretty neat online tutorial for deaf students...

DEAF SUCCEED (Deaf Educational Access For Stimulating Understanding of Collaboration, Computational science through Exploration, Experiment, and Discovery)

SubLoad Model: hydrologic and nutrient loading

Rhode Island Cooperative Extension Service spreadsheet model

(Not appropriate for use on major industrial or commercial developements as the loadings associated with these uses are not represented in the model)

DURMM: Delaware Urban Runoff Management Model

Technical Manual

User’s Manual

Spreadsheet Model


Knoxville TN Stormwater Engineering Spreadsheets

Worksheet: Computing Tc and CN

Worksheet: Initial detention volume estimates

Spreadsheets: James C Y Guo PhD PE / Colorado UDFCD

RATIONAL: Rational Hydrograph Method for Peak Runoff
UDCHANNEL: Urban Flood Channel Design
UDCHANNELFLOW: Open Channel Flow Analysis
UDCULVERT: Crossing Culvert Design and Flow Analysis
UDINLET: Street Inlet Sizing
UDRAINCURVE: Design Rainfall Distribution for Metro Denver
UDRAINZONE: Design Rainfall Statistics and PDF and IDF Curves
UDSTREET: Street Hydraulics and Allowable Capacity