Stantec shares preliminary designs

Stantec Inc. and Wildland Hydrology’s presentation of the results of their preliminary findings for the Upper North Platte River Restoration Project Friday drew mixed reactions from the public.

The project is intended to alter the North Platte River through Saratoga in order to create a self-sustaining, natural and stable river.

Hydrologist for Wildland Hydrology Dave Rosgen, suggests enhancing the river’s natural flow and building structures which mimic natural elements of the river, to create a long-term, sustainable solution for river stabilization.

The conceptual design of the project includes narrowing the river from and average 305 feet to 170 feet while increasing the depth of the river from an average of 3.9 feet to 5.3 feet. Rosgen, said increasing the width to depth ratio of the river will make the river move sediment more efficiently. It also increases channel capacity and improves habitat during low flows.

Preliminary results in the report indicate that all 12 river restoration objectives can be met to varying degrees. Some of these objectives include minimizing sediment deposition, limiting bank erosion, reducing the flood stage and protecting public and private infrastructure.

Some homeowners who live alongside the river could see their properties expanding. The design suggests many areas, especially around Veterans Island, the Wyo 130 bridge and areas around the Pick Diversion, be filled in to prevent bank erosion.

While some residents welcomed the idea of larger properties, others were concerned.

Saratoga resident Bob Thrasher said at the public forum he was troubled with the expansion of a bankfull bench (earthen fill designed to increase the height of the river bank and prevent water flowing into the floodplain) near the highway 130 bridge. He said many people who had houses on the river would no longer have a house on the river if this project is completed as designed.

Stantec engineer Dave Bidelspach, who has been working on the project, said even if the project is completed, it will do little to lower the flood stage through town. Due to the constraints of bedrock, infrastructure and potential damage to the hot pool, engineers are limited on how deep they can dig into the river.

Additionally, Bidelspach explained uncontrolled water discharge upstream means the flood stage cannot be significantly lowered — meaning there will always be a risk of flood for Saratoga residents.

However, Rosgen said the design will help reduce the flood hazard caused by sediment deposition.

“There are going to be flood issues,” Rosgen said. “That’s a reality. The restoration ... is designed to help reduce the frequency of flooding to where if we allow that sediment to continue to deposit, it is going to continue to add risk to the flood hazard at a higher probability among frequent floods. But we don’t want to misstate the reality. By doing this reshaping, it is not going to stop the flooding.”

The project is only in preliminary stages, and there are still several steps left to before any type on construction commences.

If continued, the overall construction will cost anywhere from 3.2 to 4.8 million.

Glenn Leavengood, with the Saratoga-Encampment-Rawlins Conservation District, said now that a preliminary design has been completed, they can start to receive grants to continue the project.