WDRWS Engineering Team Update

The engineering team of AE2S, Black and Veatch (BV), and KLJ have been developing a conceptual design for a primary water transmission system that would bring Missouri River water to the Rapid City metro area. Portions of the initial route followed Highway 14. 

In early November, the conceptual design teams conducted a field reconnaissance survey of the initial route as developed by South Dakota Mines in 2018. During that survey it was determined that the route following Highway 14 would have construction challenges routing around communities located along the highway. In addition, there would be additional construction challenges due to the proximity of the Bad River along this corridor. As a result, the conceptual design teams evaluated an alternative route that would move the transmission pipeline further north. This route will potentially save hundreds of millions of dollars in construction costs by eliminating the construction challenges of the more southern route, and by shortening the route. 

The engineering team has been simultaneously working on multiple intake evaluations, led by BV. The efforts have been evaluating intake options in both Lake Oahe and the Missouri River below Lake Oahe. A third alternative is looking at converting an irrigation pumping facility located adjacent to the Lake Oahe Power Plant into a supply source for the project. Design concepts have been developed for all three alternatives. Cost estimates for the alternatives will be completed in Quarter 4 of 2024 and presented to the Board of Directors at their December 2024 meeting. 

Alternative 1 — Lake Oahe Water Supply Intake 

Alternative 2 — Missouri River / Lake Sharp Water Supply Intake 

Alternative 3 — Bureau of Reclamation Pumping Facility (adjacent to Oahe Dam Power Plant) 

Conceptual capital and electrical demand costs were developed as shown in Table 1 for each alternative to use as a basis for comparison and recommendation for a preferred water supply alternative.