Montana-Dakota Utilities’ Heskett Station is adjacent to the Missouri River in Morton County, North Dakota. Due to several factors—the facility’s age, a high groundwater table, the absence of a positive drainage gradient toward a natural outfall, and the insufficient conveyance capacity of existing drainage infrastructure—rainfall and snowmelt frequently flooded the plant’s 115 kW switchyard. Because the floods created standing water adjacent to energized transformers, the situation posed a safety risk.
Barr was hired to determine the existing-conditions hydrology for the drainage area; use that to develop options for alleviating flooding; and prepare construction plans and specifications for the selected option. MDU needed a design that wouldn’t require upgrading an existing lift station, and that would receive buy-in from the facility staff members responsible for managing and operating the switchyard on a daily basis. A particular challenge was that work needed to be conducted within and adjacent to a fully energized switchyard containing overhead and underground cables, live gas lines, and other hazards, requiring a solution that could be implemented with small construction equipment.
Barr developed six options representing a range of implementation scenarios and costs to address the flooding issue. Working with facility staff and operators, MDU’s project manager chose the design that best accommodated workers’ needs and the utility’s budget.