AESI, in collaboration with Western EcoSystems Technology, conducted wetland delineations and rare plant surveys across six sites in Yellowstone National Park for the National Park Service. Spanning approximately 230 acres, these surveys aimed to identify sensitive environmental areas to guide heavy equipment placement for future fuel treatment projects. AESI utilized sub-meter GPS technology to record wetland boundaries, captured site photographs, and integrated data onto geo-referenced aerial imagery and U.S. Geological Survey maps. Additionally, field teams mapped ordinary high water marks for stream channels and water bodies within the project areas. The final reports provided detailed classifications of palustrine emergent and palustrine forested wetlands, including key vegetation and hydrology characteristics essential for boundary determinations.

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The project faced a tight timeline, as the contract was awarded in mid-August, leaving limited time to plan and complete the field surveys within the short growing season. This constraint required rapid mobilization and efficient execution to ensure accurate data collection before seasonal changes impacted plant identification and wetland assessments.

AESI quickly developed a comprehensive field survey plan, streamlining methods, sampling protocols, and safety measures to maximize efficiency. Field teams worked within the constrained timeframe to collect high-quality data, ensuring thorough documentation of wetland boundaries and rare plant locations. The final reports provided the National Park Service with precise maps and detailed environmental assessments, supporting informed decision-making for future land management and conservation efforts.

Powell Dam, an embankment dam located on the Montana Correctional Enterprises (MCE) Ranch, is classified as a high-hazard structure with a normal storage volume of 200 acre-feet. Due to its steep embankment slopes, high uncontrolled seepage rates, and past stability concerns, rehabilitation was necessary to ensure long-term safety and functionality.

AESI conducted detailed five-year engineering inspections of Powell Dam in 2014, 2019, and 2024, identifying key deficiencies that informed the rehabilitation design. Our team also assisted MCE in securing funding by preparing applications for DNRC Renewable Resources grants and FEMA High Hazard Potential Dam (HHPD) grants. The project required close collaboration with MCE, DNRC, and Montana Disaster & Emergency Services to navigate regulatory requirements and funding processes.

Key project tasks included a site visit, topographic survey, dam breach and inundation modeling, spillway capacity analysis, slope stability assessments, and embankment rehabilitation design. AESI compiled these findings into a comprehensive design report, outlining solutions to enhance the dam’s structural integrity and mitigate potential risks.

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The project was phased to align with funding availability, requiring careful planning to match grant cycles and budget constraints. Additionally, to meet cost-share requirements and reduce overall construction expenses, select construction tasks were assigned to MCE Ranch’s Job Corps labor program, necessitating coordination between engineers, contractors, and workforce trainees.

AESI’s efforts have successfully secured two DNRC grants and one FEMA HHPD grant, with an additional construction-phase HHPD grant pending award. The rehabilitation design is now complete, and construction will commence once full funding is secured. By strategically phasing the project and leveraging available resources, AESI helped ensure a cost-effective and well-planned path toward improving Powell Dam’s safety and reliability.

AESI conducted hydraulic analysis and floodplain mapping for the Milk River and selected tributaries in Phillips County, Montana, as part of a comprehensive floodplain study led by MT DNRC in collaboration with FEMA and FEMA contractors. The study was designed to comply with federal and state standards and will serve as the foundation for the county’s Flood Insurance Study and updated Flood Insurance Rate Maps.

DNRC divided the project into 23 modeling domains, assigning AESI responsibility for Domains 8-14. Using 2D hydraulic modeling in HEC-RAS and floodplain mapping in ArcMap, AESI played a key role in advancing flood risk assessment methodologies. As one of the first firms in Montana to implement 2D floodway modeling, AESI’s analysis allowed for more precise mapping of complex flow patterns in flat and sinuous terrain, incorporating irrigation infrastructure and non-levee features that influence floodwater movement.

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The study required detailed hydraulic modeling, particularly in Domain 11, which encompassed the town of Malta and demanded the highest level of precision in Phillips County. Additionally, the presence of Dodson Dam added complexity to flow modeling and flood risk assessment. Ice jam formation along the Milk River presented another challenge, requiring specialized analysis to account for seasonal flood risks.

AESI successfully completed one of the first 2D floodway modeling projects in Montana, enhancing the accuracy of flood risk assessment in the region. By leveraging advanced hydraulic modeling techniques, AESI provided a more detailed and realistic representation of flood behavior, improving floodplain delineations and risk mapping. These results will contribute to better-informed flood management decisions and updated regulatory tools for Phillips County.

AESI was contracted by the U.S. Forest Service (USFS) Region 1 to develop Emergency Action Plans (EAPs) for four high-hazard dams located in Montana, North Dakota, and South Dakota. The project included comprehensive dam break evaluations following USFS and Bureau of Reclamation guidelines, utilizing HEC-RAS 2D modeling to simulate inundation scenarios from dam failures. AESI created detailed inundation maps using ArcMap for both “sunny day” failures and Probable Maximum Flood (PMF) breach scenarios.

In addition to preparing the EAPs, AESI facilitated dam safety exercises involving USFS personnel, emergency management agencies, state transportation departments, and the National Weather Service. These exercises tested response protocols and provided critical insights for refining emergency procedures. To support ongoing dam monitoring, AESI partnered with AMCI Wireless to install automatic data loggers, enabling real-time reservoir water level tracking.

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The project required extensive coordination among multiple agencies and USFS personnel across different states. Organizing dam safety exercises involved aligning schedules, ensuring participation from key stakeholders, and structuring discussions to effectively evaluate emergency response capabilities. Additionally, the development of accurate breach inundation maps required advanced hydraulic modeling to account for varying dam failure scenarios.

Through careful planning and stakeholder engagement, AESI successfully facilitated dam safety exercises that fostered productive discussions on emergency response procedures. These exercises provided agencies with a clearer understanding of their roles and responsibilities during a dam emergency. The finalized EAPs incorporate real-world feedback from these exercises, improving preparedness for potential dam failures. Additionally, the installation of automated data loggers enhances real-time monitoring capabilities, providing USFS with critical reservoir level data for ongoing dam safety management.

AESI was contracted by Montana State University (MSU) to update their Water Facility Plan. The MSU campus is quickly expanding in both the number of buildings and the number of students/faculty, so planning for the maintenance and upgrades of the water distribution system is an important task. AESI’s engineers utilized Bentley’s WaterCAD computer software to model the existing MSU water distribution system and identify any current issues, which included fire hydrants being unable to deliver the needed fire flow, low system pressures, high velocities in pipes, major system leaks, and areas not receiving sufficient supply. Once any problems with the existing system were identified, scenarios were created in the computer model to analyze the potential solution. AESI engineers then recommended the best solutions for each issue to MSU. Lastly, AESI developed model scenarios based on likely future development within the campus. Campus populations and water usage trends were analyzed in detail to build these scenarios. Future development scenarios analyzed the feasibility of delivering sufficient water supply to new buildings and a continuously growing campus population while still meeting regulatory requirements of minimum/maximum system pressures, system velocities, and fire flow.

The MSU Water Facility Plan Update required intimate knowledge of pressurized water networks and computer-based modeling. It also relied heavily on excellent data management. The project’s greatest challenge was creating and calibrating an accurate model of the MSU water system. This challenge was overcome by isolating the MSU system from the City of Bozeman’s water system. By isolating the private water system from the public network, AESI was able to calibrate the model nearly perfectly to match real hydrant tests and simulate day-to-day conditions, providing confidence that proposed scenarios would be reliable. AESI’s wealth of knowledge with water systems and how to model them made this project a success.

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The MSU Water Facility Plan Update project presented several challenges that required a combination of technical expertise, innovative problem-solving, and meticulous data management. One of the most significant challenges stemmed from the rapidly expanding MSU campus, which placed increasing demands on the water distribution system. This growth introduced numerous issues, including fire hydrants unable to deliver sufficient fire flow, low system pressures, high pipe velocities, major system leaks, and areas experiencing inadequate water supply. Identifying and addressing these complex issues within an interconnected system required a precise and comprehensive approach.

Another major challenge was developing an accurate and calibrated model of the MSU water system. The task was complicated by the need to isolate the university’s private water network from the City of Bozeman’s public water system, as any overlap could distort the model’s accuracy. Ensuring the model aligned with real-world conditions, such as hydrant flow tests and daily water usage patterns, was critical to building confidence in the reliability of proposed solutions.

Planning for future campus development added another layer of complexity. The project required detailed analysis of population growth, water usage trends, and campus expansion scenarios to predict whether the system could meet future demands. These predictions had to account for regulatory requirements, such as maintaining minimum and maximum pressures, controlling system velocities, and ensuring adequate fire flow for new developments, all while accommodating a continuously growing population and infrastructure.

To tackle the challenges of the MSU Water Facility Plan Update, AESI used Bentley’s WaterCAD software to model the university’s water system, identifying key issues like inadequate fire flow, low pressures, high velocities, leaks, and insufficient supply. By isolating MSU’s private water network from the City of Bozeman’s system, AESI calibrated an accurate model, ensuring reliable solutions.

The team proposed targeted upgrades to resolve current issues and developed future scenarios based on campus growth projections. These scenarios ensured regulatory compliance for pressures, velocities, and fire flow, providing MSU with a comprehensive, adaptable plan for its expanding water system.

Rabbit Creek Dam, a zoned earthfill structure southwest of Reva, South Dakota, serves as both a water retention facility and a roadway embankment for Highway 79. AESI was contracted by USFS Region 1 to conduct a comprehensive safety inspection, hazard analysis, and geotechnical investigation to assess the dam’s stability and risk profile.

The project included a full Potential Failure Mode Analysis (PFMA), a risk-based geotechnical assessment, and detailed stability modeling of the embankment. AESI evaluated seismic hazard and liquefaction potential, conducted an overtopping hydraulic scour study, and used advanced numerical modeling tools such as SLOPE/W for stability analysis and SEEP/W for seepage analysis. Additionally, drone survey data helped identify potential weak points, including low areas and possible sinkholes.

A key focus of the hazard analysis was reassessing the dam’s classification, which had previously been designated as Significant Hazard. However, prior evaluations had not accounted for the fact that Highway 79 runs along the embankment, posing a direct threat to motorists in the event of failure. Based on AESI’s findings, the classification was recommended for an upgrade from Significant to High Hazard. Following this assessment, AESI was contracted to conduct a feasibility study for dam decommissioning and later to develop a design for the selected decommissioning alternative.

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The hazard analysis required a detailed evaluation of complex failure modes, necessitating extensive numerical modeling to simulate different risk scenarios. Advanced tools such as HEC-HMS, SLOPE/W, and SEEP/W were used to analyze hydrologic and geotechnical conditions. Accurately assessing the dam’s failure impacts and potential life-safety risks demanded close coordination with USFS and a thorough review of all available data.

AESI’s comprehensive analysis led to the hazard classification being raised to High, in part due to the increased risk to motorists on Highway 79. This reclassification informed USFS decision-making, ultimately leading to the selection of dam decommissioning as the preferred course of action. AESI’s subsequent work on the feasibility study and decommissioning design ensured that the project moved forward with a well-documented and technically sound approach, prioritizing public safety and long-term site stability.

AESI conducted a comprehensive infrastructure risk assessment for 17 large culverts and tunnels beneath earthen railroad embankments along the Route of the Olympian in Mineral County, Montana. These culverts, originally constructed over 100 years ago by the now-defunct Milwaukee Road Railroad, had not been maintained for more than 50 years, presenting significant structural and hydraulic risks. The purpose of the study was to evaluate geotechnical and hydrologic failure risks and prioritize necessary repairs.

The project involved advanced geotechnical explorations, drone aerial surveys, hydrologic and hydraulic modeling, and slope stability design. AESI utilized Monte-Carlo simulations and numerical modeling to develop a “reliability index” ranking from 0 to 1 for each culvert, providing a data-driven approach to risk assessment. A UAV drone was used to gather 3D topographic survey data in remote areas, while software tools such as Slope/W and HY-8 helped assess the geotechnical and hydraulic reliability of each structure. The final Geotechnical Investigation Report outlined repair prioritization strategies and detailed various rehabilitation options, ranging from cleaning and lining to full replacement using micro-tunneling techniques.

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The project presented unique challenges due to the age and deteriorated condition of the culverts, the lack of prior maintenance records, and the complexity of assessing massive earthen embankments. Additionally, the remote location and varying terrain required innovative survey and modeling approaches to accurately evaluate structural integrity and failure risks.

AESI’s analysis provided a clear and systematic approach to culvert remediation planning. The final report delivered prioritized repair recommendations based on geotechnical, hydraulic, and structural risks, giving USFS Region 1 a valuable tool for phased infrastructure improvements. By integrating advanced modeling techniques and risk-based evaluations, AESI ensured that repair efforts would be strategically targeted to maximize safety and cost-effectiveness.

“[AESI] professionally provided insightful, effective, and efficient engineering innovations that achieved or exceeded all needs and expectations. The product of this effort is a report with clear narrative, colored tables, and graphic displays that is immediately a very constructive tool for managers to being remediation planning.” – Traci Sylte, USFS