The Bassett Creek Watershed Management Commission hired Barr to update and recalibrate its hydrologic and hydraulic (XP-SWMM) model. Barr refined the subwatershed divides using existing water-quality model subwatersheds, current topographic data, and storm sewer data—delineating and modeling more than 1,150 subwatersheds. The model was also updated to accommodate runoff flows generated from Atlas 14 design storm events. The revised XP-SWMM model was calibrated using NEXRAD precipitation data along with flow and elevation monitoring data for two storms. Once calibrated, the model results were verified against the monitoring data for a third storm.

Barr then used the calibrated model to analyze the Atlas 14 100-year, 24-hour design event to characterize flow conditions in the watershed and along the creek to predict the 100-year flood elevations. Approximate inundation mapping of the 100-year, 24-hour event was developed using XP-SWMM model results and current topographic data. Results of the model update and calibration process were documented in a technical report.

In 2018, FEMA awarded a grant to the Minnesota Department of Natural Resources for updating the special flood-hazard areas within Minneapolis and St. Paul, preferably by leveraging existing models wherever possible. The DNR recognized the value of the Phase 2 XP-SWMM model and worked with the commission to enter into a pass-through funding agreement to update the model to meet FEMA modeling standards. The primary focus of the update is to modify the model based on surveyed data for hydraulic structures.

Barr, in partnership with the University of North Dakota (UND), Microbeam Technologies Inc. (MTI), Envergex, LLC, and MLJ Consulting, worked to develop a transformational technology that controls the formation of alkali aerosols found in coal ash. This technology mitigates ash deposition by injecting sorbents into the boiler and capturing volatile species that act as glue for ash deposition and growth, the primary cause for boiler outages.

Control and mitigation of ash deposition is expected to increase plant revenues due to a reduction in outage time, create a better heat rate efficiency reducing boiler temperatures, reduce NOx emissions from lower furnace temperatures and deeper staging, improve heat rate reducing fuel consumption and improve fuel flexibility/tolerance for low-quality fuels.

As part of the Transformative Power Generation Program (TPG), this project develops near to long-term technology options for flexible, reliable, and cost competitive coal-based power generation at both new and existing plants.

A confidential client owns and operates a 54-mile natural gas pipeline that crosses five counties in southeast Michigan. To increase pipeline capacity, the client sought to replace and upsize the aging pipeline with a 36-inch diameter pipeline. Barr was hired to assist with environmental field reviews related to regulated wetlands, streams, and floodplains as well as threatened and endangered (T&E) species. We also assisted the client with addressing comments from the Michigan Public Service Commission (MPSC) during the Public Act 9 filling process. Services we provided during the project include:

Award-winning stormwater planning and design for a new Saint Paul community 

When the City of Saint Paul began planning the transformation of Ford Motor Company’s former Twin Cities Assembly Plant into Highland Bridge—a new mixed use neighborhood along the Mississippi River—stormwater management was a central challenge. The redevelopment project needed to protect the long-term health of downstream Hidden Falls Creek, where uncontrolled storm flows had caused erosion and ecological degradation. The city and the Capitol Region Watershed District (CRWD) sought a solution that would not only treat stormwater runoff but also support broader sustainability, habitat restoration, and public space goals for the new neighborhood.

The city and CRWD hired Barr in 2007 to conceptualize a district stormwater management system. Through detailed hydraulic and water quality modeling and a triple bottom line analysis, Barr demonstrated that a centralized system with a single open-water feature would far outperform a conventional parcel-by-parcel system. The water feature, a half-mile-long stormwater pond leading to a reimagined creek channel, would trace the historic headwaters of Hidden Falls Creek, long buried beneath the former assembly plant, and offer greater ecological, social, and economic value. 

Ryan Companies US, Inc., the developer, then hired Barr to complete the final design. The new district stormwater management system directs all runoff from Highland Bridge to 10 treatment features: five large rain gardens constructed with iron enhanced sand and five underground storage and filtration basins. Together, these features remove sediment and phosphorus from stormwater before it enters the pond, preventing 28 tons of sediment and 147 pounds of phosphorus from reaching the Mississippi River each year. The pond holds all runoff from storms up to the 100-year event and reduces peak discharges to Hidden Falls Creek by 98 percent during a two-year storm—dramatically decreasing downstream erosion. 

By integrating stormwater management features with parks, trails, and gathering spaces, the system conserved approximately 10 acres of developable land while enhancing Highland Bridge’s abundant open space and community amenities. Barr further supported the city by helping establish a regulatory “green infrastructure overlay district” to guide the management and cost-sharing of centralized stormwater infrastructure.

Fully operational since 2023, Highland Bridge’s district stormwater management system is the first of its kind in Saint Paul, the largest of its kind in Minnesota, and a model for 21st-century sustainable urban redevelopment. 

A state-run correctional center uses a system of three lagoons to treat wastewater from the correctional facility and its institutional laundry operation. The state hired Barr to design changes to the system so it would more reliably meet current and future permit limits, including those for total suspended solids, ammonia-nitrogen, and E. coli.

Our wastewater team evaluated the system’s condition and design capacity; developed a number of options for improving performance of the system; prepared planning-level costs for the options; and developed project phasing options for the state’s consideration. 

The treatment-process modifications Barr evaluated included sludge removal from the lagoons; changes to the amount and type of aeration employed; addition of fixed-film nitrification; addition of ultraviolet disinfection; and potential closure of at least one lagoon. 

Under the U.S EPA’s Great Lakes Water Quality Agreement, the U.S. and Canadian governments agreed to restore and maintain the physical, biological, and chemical integrity of the Great Lakes. Lakewide action and management plans, known as LaMPs, provide blueprints for assessing, restoring, protecting, and monitoring the ecosystem health of each lake and its connecting river system.

Lake Superior’s LaMP includes a zero-discharge demonstration program aimed at eliminating the anthropogenic emission and discharge of nine bioaccumulative substances, including mercury, dioxins, and pesticides, into the Lake Superior basin by 2020. Every five years, the program assesses the progress made toward that goal.

Working with Battelle and coordinating with our Canadian counterpart, Barr developed the 2015 U.S. chemical source inventory pertaining to the program’s reduction target. Our work included updating data on emissions, discharges, sources, and spills of the nine substances in the Lake Superior watershed; calculating yearly production data and population-based loads for each substance; preparing graphs and tables presenting the updated information, and recommending strategies for further reducing emissions and discharges.

The Ford Marsh Unit of the Detroit River International Wildlife Refuge (DRIWR) is a 242-acre wetland near Monroe, Michigan. Due to a legacy of heavy industrial development in the region, Ford Marsh represents some of the last remaining coastal wetlands in the western basin of Lake Erie and is an important habitat for migratory populations of waterfowl, shorebirds, and landbirds. The marsh was privately managed by hunting clubs for more than 100 years before the U.S. Fish and Wildlife Service (USFWS) acquired it in 2009 and incorporated it into the DRIWR. 

Beginning in 2017, multiple years of high Lake Erie water levels coupled with seiches (sudden water level rises caused by strong winds and rapid changes in atmospheric pressure) resulted in severe damage and habitat degradation to Ford Marsh. As a result of the damage, the USFWS’s ability to effectively manage Ford Marsh was lost, and the marsh’s productivity, diversity, and ecological function were greatly compromised.

In 2021, USFWS hired Barr to develop and evaluate options for restoring desired wetland functions to Ford Marsh, asking us to use a holistic approach to uncover and address the root causes of the marsh’s lack of resiliency. In pursuit of this goal, we acquired and assessed data on recent and anticipated future trends in Lake Erie water levels, storm frequency and magnitudes; nearshore currents, sediment transport and deposition patterns; Lake Erie and Ford Marsh bathymetry and topography; the geotechnical stability of an existing dike system; and vegetation and natural community inventories and mapping. In addition, Barr hosted stakeholder engagement sessions to solicit input from neighboring landowners and representatives from federal and state agencies. Using these findings, we developed multiple restoration concepts and evaluated each design concept for feasibility based on a decision matrix of solution effectiveness, constructability, embrace by stakeholders, and anticipated construction costs.

USFWS accepted Barr’s findings and is evaluating the identified restoration options with the goal of selecting a preferred option to advance to detailed design.

NewRange Copper Nickel LLC (formerly PolyMet Mining Corporation ) needed a National Pollutant Discharge Elimination / State Disposal System (NPDES/SDS) permit for their proposed NorthMet Project. Located at the northern end of Minnesota’s Iron Range, the NorthMet Project includes an open pit copper-nickel mine, a beneficiation plant, and a tailings basin. To receive an NPDES/SDS permit, they needed to demonstrate that they would comply with state and federal regulations for the discharge of industrial wastewater and management of stormwater, as well as operation of the tailings basin, stockpiles, and ponds. 

Barr had worked with PolyMet throughout the environmental review process and had a thorough understanding of the project and the estimated environmental effects. Before environmental review was complete, PolyMet engaged Barr to begin planning for permitting.

Barr worked with PolyMet to develop a permitting strategy and then implement it. Results of multiple models , including GoldSim and Modflow, were used to document that the project could meet state and tribal water quality standards. Many meetings with Minnesota Pollution Control Agency staff were vital to developing a shared understanding of the anticipated effectiveness of the project’s environmental controls.

One unique consideration was that the plant site was to be constructed at a former taconite processing facility, where the groundwater was contaminated by seepage from the legacy tailings basin. This meant that the NPDES/SDS permit application needed to show that PolyMet would not only manage pollutants from their operations but would also improve the legacy pollution.

Another unique circumstance was that Minnesota’s antidegradation rules were changing while the permit application and draft permit were being developed. It was unclear which set of rules would be in place when the permit was issued, so Barr developed a permit application that demonstrated compliance with both the old and the new antidegradation rules. The permit application was deemed complete, and in December of 2018, PolyMet was issued an NPDES/SDS permit for the NorthMet Project.

During 2015 and 2016, Barr assisted the MPCA with content updates to the infiltration sections of the Minnesota Stormwater Manual. This wiki-style document is used by stormwater practitioners to select and implement the most effective and cost-efficient BMPs for managing stormwater runoff volume and pollutants and to meet stormwater permitting regulatory requirements. Updates included the overview, types of infiltration, design criteria, cold-climate suitability, construction specifications, and operation and maintenance of infiltration practices.

In addition, we created new guidance for understanding and interpreting soils and soil-boring reports as well as new case-study summaries of infiltration project examples. The types of infiltration practices discussed included the infiltration basin, infiltration trench (including tree trench/tree box), bioinfiltration, permeable pavement, swale with check dam, drywell, and underground infiltration measures. The deliverables included illustrations that allow users to distinguish the various properties of each BMP, as well as schematics to show updates to technical terms for design criteria.

Other deliverables included selection matrices to help choose infiltration media, examples of access and maintenance agreements and easements, and inspection forms and checklists for design, construction, and post-construction operation and maintenance.

The manual can be found on the MPCA’s website at https://stormwater.pca.state.mn.us/index.php?title=Main_Page.

Barr also worked with the MPCA to develop an infiltration-practices webinar (https://youtu.be/WRAVEmR4ExI) based on content developed for the manual.

The Upper Sheyenne River is a 300-mile segment of the Sheyenne River in north-central North Dakota, flowing through nine counties that together make up the Upper Sheyenne River Joint Water Resource Board (Joint Board). In recent years the river has experienced significant bank erosion and channel migration, threatening local infrastructure in several locations. The Joint Board hired Barr to conduct an erosion and sedimentation risk assessment of the entire Upper Sheyenne River riparian corridor, from the headwaters to Baldhill Dam. The results of the risk assessment will be used to prioritize restoration activities along the river and to guide applications for project funding from federal and state grant programs.

 Our work included background data collection and public meetings to identify key areas of concern, field surveys at 15 locations along the river to characterize typical channel dimensions and evaluate bank stability, and analysis and risk assessment. The risk assessment used the Rapid Resource Inventory for Sediment and Stability Consequences (RRISSC), a component of the Watershed Assessment of River Stability and Sediment Supply (WARSSS) methodology (Rosgen, 2009).

 The risk assessment found that 18 of the 30 river reaches in the study area are at high risk for ongoing channel instability. Barr prepared concept stabilization recommendations for several of the study locations.