Bend Bulletin: Funding secure for Mirror Pond Dam fish passage design phase
For more than a century, the Mirror Pond Dam in downtown Bend has blocked fish migration in the Deschutes River. Now officials say they are making progress in building a fish passage to help rainbow trout and other species get around the dam.
Kris Knight, the executive director of the Upper Deschutes Watershed Council, says $409,000 has been secured for the engineering and design phase of the fish passage project. This phase is expected to begin this year, with completion planned for 2026, Knight said.
Building a fish passage around Mirror Pond Dam has been a decade-long effort by Bend Park & Recreation District, the city of Bend and conservation groups. The so-called Mirror Pond Vision, created by the community in 2015, recommended retaining the pond — the smooth, slow-moving section of the Deschutes created by the dam and bordering Drake Park — while enhancing the environment around it.
The hydroelectric dam — built in 1910 as a producer of energy for the young city — is owned by PacfiCorp, which continues to generate power from the dam.
Barrier to fish
While the dam’s existence created iconic Mirror Pond, a landmark in Bend, it also represents a barrier preventing fish from finding suitable habitat necessary for their lifecycle. It is the last dam in Bend that blocks fish passage.
Over the past decade, modifications were made to two other dams in Bend allowing fish passage. A dam near Colorado Avenue was removed, allowing the construction of the Bend Whitewater Park. The North Unit dam, located near Division Street, was outfitted with a fish ladder in 2017.
The North Unit dam fish ladder has been monitored since 2018. Ben Stout of the Oregon Department of Fish and Wildlife said redband trout, mountain whitefish and brown trout regularly use the ladder to pass upstream, with most activity occurring between March and October.
Fish passage funders
Major donors for the engineering and design phase include the Oregon Watershed Enhancement Board ($136,000) and The Oregon Department of Fish and Wildlife ($261,000). There is another $12,000 left over from a feasibility study, provided by U.S. Fish and Wildlife, which can be used for engineering design.
“We expect that funding will cover all the costs associated with engineering design but additional funds will be needed for permitting and eventually construction,” Knight said.
The Upper Deschutes Watershed Council, a non-profit based in Bend, will manage the grant funds and convene organizations and contractors to complete the engineering design effort.
Nature-like fishway
The passage is described as a “nature-like fishway” that is designed to mimic stream conditions, similar to the fish passage at the Bend Whitewater Park. That passage — used by inner tubers who float the river — consists of a series of drops and pools that fish can use to navigate their way upstream or downstream.
A benefit of the nature-like fishway, Knight told Bend Park & Recreation District board members recently at a briefing, is that its materials could be disassembled and repurposed in the river if the dam is ever decommissioned and removed.
But he added a word of caution. While the fish passage will create an “upstream opportunity” for fish, those headed downstream could get pulled into PacifiCorp’s hydroelectric facility.
“We are taking this in a stepwise fashion,” said Knight. “We are creating this upstream passage and we hope to design that in a way that will encourage fish to go downstream through the fishway as well. We hope some creative solutions will come as part of this design effort.”
PacifiCorp involvement
As owner of Mirror Pond Dam, PacifiCorp says it will be involved in the development of the fish passage, although it isn’t saying exactly how much it plans to offer in terms of funding.
When asked by The Bulletin about funding levels, PacifiCorp spokesperson Pampi Chowdhury said the utility will “support” the community-led effort and further details of that support will be known in later stages of its development.
Chowdhury did not directly respond when asked about the lifespan of the dam, saying only that PacifiCorp has performed work on the dam in recent years “to enable continued operations of the project.”
Fishway over fish ladder
The latest development follows earlier work by the Mirror Pond Fish Passage Advisory Committee, created by Bend Park & Recreation District and the city of Bend in 2021. That committee was focused on creating a fish passage while also allowing PacifiCorp to retain the dam.
Two years ago, the committee agreed to go ahead with a nature-like fishway instead of a fish ladder.
“A traditional concrete fish ladder was selected as a back-up alternative if a nature-like fishway was deemed not possible as part of the planning and design effort,” said Knight.
More will be known about construction costs of the fishway after the engineering and design phase, Knight said.
“There are still many steps before this project is a reality but it is exciting to be one step closer by securing the funding for engineering design for the fishway,” he said.
