City dives back into West Dam

Jason Ferguson

The Custer City Council took the first steps in some time in getting West Dam repaired and full of water once more at its Nov. 6 meeting.
At the meeting, the council unanimously proposed agency coordination and dam advancement activities with RESPEC, an engineering consulting firm out of Rapid City.
“This is an effort to keep things moving with West Dam. We need to re-engage with the necessary authorities—State of South Dakota, (Army) Corps of Engineers, etc.,” said Trent Bruce of DGR Engineering, who was at the meeting via video conference. “This contract will allow us to initiate those conversations to facilitate the future construction work that we would like to see at West Dam.”
Bruce said RESPEC has been doing some other related hydrology work previously, and he would recommend the city approve the agreement to move forward with figuring out what can be done with West Dam.
In a memorandum to the city, RESPEC wrote allowing it to coordinate with relevant agencies would help understand the status of the dam and reservoir as well as the permit requirements for potential dam advancement activities as well as an anticipated timeline for those activities.
Under the agreement RESPEC will hold the prime contract with the city and will team with Banner as a subconsultant. Banner would have a major role in the first phase by leading the environmental coordination and survey efforts. RESPEC will coordinate with the South Dakota Department of Agriculture and Natural Resources (DARN) regarding dam safety and will serve as design lead and engineer of record as the project moves through subsequent phases.
A summary by RESPEC tells the journey of West Dam since it sprung a leak and drained in 2012. Except for a few storm events, the dam has not held water since that time.
In 2015 Banner conducted an assessment of the alternatives and presented the information in a public meeting, indicating that the dam would be regarded as a high-hazard facility due to its proximity upstream from a populated area. The community wanted the full impoundment restored, despite the fact that it was a high-hazard dam.
In 2016, Banner prepared construction plans for a new West Dam and submitted them to the (DANR). The plans were approved, and the Water Management Board issued a new water permit to the city for the re-construction of the dam. One water permit allowed for an increase in storage capacity of 47.5 acre-feet (for a total of 77.5 acre-feet). The permit conditions set the construction completion date for on or before July 6, 2024, with water being put to beneficial use on or before July 6, 2025.
In 2021, Banner completed a Custer West Dam Project Review and Project Status Update (Review) which reviewed the 2016 construction plans and provided construction cost updates, reviewed the 2020 Federal Emergency Management Agency Letter of Map Revision (LOMR) updated Base Flood (100-Year Flood) flow and reviewed permit status and new dam construction action items. The review identified significant revisions to the water surface profile in the area of Custer West Dam due to the reduction in the Base Flood flow, RESPEC wrote.
Additionally, the review identified the need for permit certifications and potential updates to the Custer West Dam Emergency Action Plan prior to new dam construction.
To date, the reconstruction project has not moved forward, and the original engineer of record has since retired. The reconstruction plan set has essentially expired unless recertified by another professional engineer without modifications. Also, FEMA has since made significant changes to the estimated flow rate of the base flood. All things considered, it has been recommended that an engineering review of design options be conducted, in subsequent phases, to determine the most effective solution for achieving the city’s goal of returning Custer West Dam to a valuable recreational amenity for the community, RESPEC wrote.
RESPEC further wrote one of the key components of completing the project is to identify the environmental requirements in the initial steps of the project.
“From an environmental compliance standpoint, we assume the implementation of dam advancement activities will require a desktop delineation of the existing wetland and stream area, evaluation of the existing water right and validity of that right, and any anticipated regulatory and permitting needs and how those needs will affect schedule, planning, and implementation,” the memo reads.
RESPEC said permits will likely be needed for the dam project to move forward, including from the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service for threatened and endangered species coordination, DANR for water rights and dam safety, South Dakota Department of Game, Fish and Parks and South Dakota State Historic Preservation Office.
The proposal will seek to identify dam activities that can take place prior to spring 2024 to help demonstrate the project is moving forward in advance of new dam construction.
The memo said RESPEC will prepare a report for the city’s review that will include a dam safety summary, potential dam advancement activities, environmental summary for each activity, activity permitting timeline and conclusion and recommendations.
The city will pay $24,500 for the work RESPEC will do in this phase, and will receive a report by Jan. 31.
In other news from the Nov. 6 meeting, the council:
• Heard from Sam Smolnisky of Custer County Search and Rescue, who told the council about SAR’s 50th anniversary celebration Saturday at  The Custer Beacon. Smolnisky also thanked the city for its cooperation on working with the county so SAR could have the lot next to its building. Smolnisky said the improved response time made possible by stationing equipment at that lot has literally saved a life recently.
• Heard from public works director Zack Brown who said the city crew is gearing up for snow-removal season, and mentioned for the public to be aware of the city’s policy on snow removal with regard to sidewalks, etc. He added private driveways are not the responsibility of the city to plow, which some residents believed.

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