Beavers to blame for big dam boondoggle
City's dam removal brings ire of neighbors near 121st Avenue
If you ask the neighbors on Southwest Merestone Court in Tigard, theres nothing more important than the large wetland and pond that stretches for acres behind their homes.
For more than 20 years, it has been the ideal habitat for fish, turtles, foxes, deer, otters and osprey. Neighbors quickly point out a pair of nesting bald eagles in a nearby evergreen.
But the most famous residents of Merestone Pond are the family of beavers whose dams helped transform the section of Summer Creek years ago.
The beavers have a longstanding feud with city workers, who say the places the beavers build their dams are threatening two culverts under Southwest 121st Avenue.
Crews have removed the dams twice in the past 15 years, and removed a portion of a third dam last Wednesday, re-sparking a contentious fight between neighbors and city officials.
The neighbors are fiercely protective of the beavers. When work crews removed a dam from the pond in 2011 which city workers said was clogging the culverts neighbors called the police.
Every time the dams are removed, it drains the pond, neighbors say, which leaves a thick layer of mud that stretches for acres. But city officials say the work is necessary to protect taxpayer-funded roads.
We do this kind of work throughout the city, said John Goodrich, Tigards utility division manager. We want to reduce the likelihood for localized flooding and erosion, and protect the riparian areas near creeks. We think that it is good for the ecology of the wetlands.
For neighbors many of whom moved to the area for the view that explanation is hard to stomach.
Right now, the pond is about 10 feet across, if that, said Sherri Grill, who has lived next to the pond for more than a decade. Its a puddle of muck out there.
The mud is unattractive, smells and brings down property values, neighbors say. But more than that, it also impacts local wildlife.
They all depend on this water, Grill said. I just cant believe the city would do this.
Cities have the authority to remove beaver dams, but Tigard has a hands-off policy toward wildlife, as long as it doesnt threaten city infrastructure, said Goodrich.
We are trying to work with the wildlife in that area, but we also need to prevent flooding for that culvert, he said.
Why remove the dam at all?
After the 2011 dam removal, the beavers built a new structure on the east side of 121st Avenue.
Liz Ruther with the Oregon Department of Fish and Wildlifes Wildlife Habitat Conservation and Management program said the dam no longer poses a threat of breaking apart and clogging the culverts. But in recent weeks, the dam built up water levels to the top of the culvert, and the city ultimately decided to remove a portion of it to help with flow.
The water level was almost to the top of the culvert, and the city was worried about debris getting caught in there and causing dangerous conditions for workers, Ruther said. They city wanted enough headspace between the water and the top of culvert.
The dam was causing other problems, too, Goodrich said.
The dam had gotten quite high, and what it was starting to do was create problems with vegetation, especially the mature trees. When they get flooded like that, it will kill them and we didnt want that.
The city removed more than a foot from the top of the beaver dam, which Goodrich said would reduce the pressure on the culvert and lower the water level.
Ruther said the city has stepped up its relationship with ODFW since the 2011 incident, which drew criticism from the state agency when it wasnt informed about the removal ahead of time.
Since the hullabaloo (in 2011), they notify me of every single plan, since this is such a sensitive issue, Ruther said.
Beavers may be trouble
Crews installed two vertical logs upstream of the culvert in 2011 in the hopes of attracting the rodents to rebuild a safe distance away, but the beavers have shown little interest in building where the city would prefer.
These beavers in particular are being really tricky, Ruther said.
Urban beavers can be troublesome for cities, but they are also an important part of the ecosystem, Ruther said.
Those beavers are doing fabulous habitat work out there, Ruther said. The area looks beautiful. Hopefully, they will continue moving around. We really want them to use the attractants.
Goodrich said that as long as the beavers dont threaten the citys infrastructure, the city has no plans on removing the dam any further.
We look at Tigard as a partner for urban beavers, Ruther said. They are a big deal for water quality and fish.
Plans are in the works to install a pipe under the dam, which would allow some water to continue to flow and not disrupt the beavers, Goodrich said.
We are trying to do things in a way that keeps the beavers there, but we also need to place limitations on how much damming and ponding they can do, Goodrich said. If we can maintain and keep things status quo, well try to do that. But certainly the most important thing for us is to provide adequate flow capacity. Nobody wants to be impacted by flooding.
Neighbors on Merestone say theres little chance of flooding in the area, and the citys meddling is making things worse.
The water belongs there, the wildlife belongs there, and they need to be left alone, Grill said.
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