Helping you test the waters by modeling the waters.

RESPEC understands the complex and dynamic relationships between water, energy, and food.  Our scientists and engineers work with clients to better understand and systematically analyze the interactions between the natural environment and human activities, and to work toward a more coordinated management and use of natural resources across sectors and scales.  RESPEC creates and applies state-of-the-science numerical models and decision-support systems to develop optimal solutions for our clients that meet stakeholder requirements and minimize risk.

RESPEC has performed environmental modeling studies, ranging in size from small to large—a few square miles to the 64,000-square-mile Chesapeake Bay Watershed. Our scientists and engineers are interdisciplinary experts in floodplain mapping and in modeling hydrology, hydraulics, groundwater, water quality, watershed, geological, and inundation.

Globally recognized as an authority on environmental modeling and decision-support systems, RESPEC makes expert recommendations to clients regarding the appropriate modeling system for their specific use.  When needed, RESPEC develops customized systems for our clients.

Modeling & Optimization Flyer


    • Hydrologic Modeling
    • Hydraulic Modeling
    • Water Quality Modeling
    • Floodplain Mapping
    • Groundwater Modeling
    • Watershed Modeling
    • Geological Modeling
    • Best Management Practice Planning
    • Engineering Software Development
    • Engineering Software Migration
    • Development of Engineering Model Application Tools
    • Engineering Model Application Support

Modeling & Optimization projects

Learn more about related projects where RESPEC has proven our expertise in this area.

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Belle Fourche Irrigation District Siphon Replacements

Providing design and construction administration services for replacing an inverted siphon pipe.

Belle Fourche River Watershed Implementation Project

Correcting sediment and bacteria impairments in and around the Belle Fourche River Watershed.

Benton County Irrigation Scheduler

Creating a web-based application (Irrigation Management Assistant) to help manage irrigation.

Big Sioux Flood Inundation System

Developing a Flood Inundation System for the Big Sioux River Basin in eastern South Dakota.

Big Sioux River Sediment and Bacteria Total Maximum Daily Load

Developing sediment and bacteria Total Maximum Daily Loads for the Big Sioux River.

Big Sioux Water Quality Trading Project

Assessing the sediment and bacteria impairments in the Central Big Sioux River Watershed and reducing pollution through a water quality trading.

Black Hills Suitability Risk Model

Using GIS to assess risk and guide development-planning decisions.

Cape Fear River Watershed Model

Developing a Soil and Water Assessment Tool model to improve water quality in the Cape Fear River Watershed.

CDOT Bridge Scour Investigation and Repair

Supporting the Colorado Department of Transportation with flood response and recovery efforts in northern Colorado. 

Cheyenne Municipal Watershed Wildfire Hazard Mitigation

Evaluating potential fire risk and water quality impacts to minimize future water supply system risks.

City of Brighton Utility Project

Providing water and wastewater services to extend city development.

Clark Fork River Plains Reach Assessment

Identifying restoration alternatives to improve conditions and restore natural channel processes while protecting critical infrastructure and economically important lands.

Coal Creek Rock Creek Master Plan

Accelerating major drainageway planning studies in Colorado.

Contribution-Based Watershed Assessments

Using local watershed data and conditions to derive improvement fees.

Dead Run Stream Restoration

Assessing channel conditions in Dead Run Stream and designing stream improvements through McLean Central and Dead Run Stream Valley Parks.

Decision-Support Tools for Watershed Management

Developing custom tools to interpret model results for watershed management.

EPA Rates Manual

Reviewing and researching nutrient-related rates, constants, and kinetics in four water quality model frameworks.

EPA Steam-Generated Power Regulation

Modeling support for revisions of the Environmental Protection Agency's regulations for Steam Electric Power Generation.

High Line Canal

Developing practical solutions for repurposing the High Line Canal for collecting and treating stormwater runoff.

HSPF Code Conversion

Modernizing HSPF modeling code to maximize results.

Illinois River Total Maximum Daily Load

Modeling water quality and developing a Total Maximum Daily Load for the Illinois River Watershed.

Middle North Platte Watershed Study

Creating an inventory of water and land resources within a Wyoming watershed.

Montana Map Modernization and Risk MAP

Providing high-quality flood maps and information to minimize threats to life and property.

Piney Creek Major Drainageway Plan

Mitigating severe channel degradation, erosion, and heavy sediment deposition in the Piney Creek drainageway.

Red River of the North Stressor-Response Model

Examining the relationships between the biological community and nutrients in the International Red River Watershed.

Saltese Flats Wetlands Restoration

Restoring the natural hydrology after a century of change.

SARA Water Quality Modeling Tool Development

Developing software tools to facilitate watershed modeling and planning in San Antonio River Authority’s (SARA) watersheds.

Spring Creek Watershed Restoration

Keeping streams clean in the Black Hills.

Statewide Water Quality Program Support

Supporting the Colorado Department of Transportation's statewide water quality program.

Story Mill Community Park Stream Restoration

Restoring ecological functions to a riverine system in an urban environment around a community park.

SWMM Stormwater Planning Plug-In for Open Planning Tools

Creating new tools for computing stormwater runoff in urban areas.

SWMM/EPANET User Interface Reengineering

Updating software user interface that is designed to manage input data, drive specialized simulations, and analyze output data that are user-friendly.

Temperature Total Maximum Daily Load Assessment

Supporting aquatic life by defining allowable heat loads and implementation plans for streams in the Black Hills.

US Highway 24 Fountain Creek and Waldo Canyon

Evaluating damage and mitigation options after devastating fires and severe flooding in Colorado.

Using Basins.MIL to Evaluate Climate Non-Stationarity

Understanding and managing the potential impacts of climate change and land-use change at a watershed scale.

Water Conservation Belle Fourche Irrigation District

Improving water-use efficiency using an overall water management system.

Yellow Medicine Project – One Watershed One Plan

Guiding southwest Minnesota partners to develop the next generation of watershed planning for the Yellow Medicine River.
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Modeling & Optimization products

RESPEC’s product line is geared toward making businesses and organizations better, faster, smarter, and safer. Our products benefit clients in need of greater efficiency, accuracy, and cost savings.

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BASINS integrates environmental data, analysis tools and watershed and water quality models to assist in managing watersheds and developing Total Maximum Daily Loads (TMDLs).


HSPEXP+—An enhanced expert system for calibration of HSPF.

Hydrologic Simulation Program‑FORTRAN (HSPF)

Hydrologic Simulation Program‑FORTRAN (known as HSPF) is an analytical tool that has applications in planning, designing, and operating water-resources systems. 

Hydrologic Simulation Program–Python (HSP2)

RESPEC’s Hydrologic Simulation Program–Python (HSP2) model uses modern technology to improve upon its predecessor Hydrologic Simulation Program–FORTAN (HSPF) model.

SARA Load Reduction Tool  

SARA Load Reduction Tool — Allowing users to determine the constituent load reductions needed to reach water quality standards in model reaches within a watershed.

SARA TS Utility  

SARA Timeseries Utility supports the analysis and management of time-varying environmental data.

Scenario Application Manager (SAM)

RESPEC’s HSPF Scenario Application Manager (SAM) is a comprehensive decision-support tool for planning and implementing targeted actions to restore or protect water quality.

Storm Water Management Model (SWMM)

RESPEC reengineered the user-interface architecture for the Environmental Protection Agency's Storm Water Management Model (SWMM) and EPANET.
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Tony Donigian, PE, D.WRE
Manager, Watershed Modeling

Jason Love, PE
Senior Vice President, Water & Natural Resources