Our Voice: State responsible for mitigation if Bateman causeway breached

If state officials want to breach the Bateman Island causeway to improve salmon runs, then they need to consider mitigation as well.

A study last year showed that removing the causeway connecting Bateman Island to the main shoreline would decrease the water temperature in the Yakima River delta. This cooler water, researchers believe, would help salmon and steelhead.

We certainly are in favor of helping salmon survive, but not at the expense of destroying public access to the island or ruining the habitat of other species currently thriving there.

Balance must be the goal.

Bateman Island is a popular, 160-acre natural land mass that is heavily used by walkers, hikers and others — especially bird watchers. The Lower Columbia Basin Audubon Society often uses the island for its bird tours, which attract dozens of participants.

But the causeway acts like a dam, and has long been blamed for helping raise the water temperature at the mouth of the Yakima River. It blocks the channel running between the island and the Columbia River, creating a stagnant pool. This warm body of water supports mosquitoes and predatory fish that feed on the juvenile salmon trying to reach the Pacific Ocean.

Researchers say if the water was cooler, it would not be as easy for smallmouth bass and walleye to digest other fish like salmon, and they likely would not eat as much.

And that means more juvenile salmon would have a better chance of ending up in the ocean instead of another fish’s belly. Colder temperatures would help returning salmon access the Yakima as well.

In addition to preserving public access, any state proposal should also consider what changes might happen to the river current if the causeway was breached

Officials with the city of Richland and Visit Tri-Cities already are asking the state to protect the Columbia Park West Marina from up to 1.9 knots of new river current.

This is a completely reasonable request.

Kris Watkins, president and CEO of Visit Tri-Cities, said in a letter to the regional Fish and Wildlife director that the marina was not designed, built, permitted or insured to withstand a stronger river current.

Any proposal by the state to breach the causeway must consider the ramifications of changing river flow. The causeway also has created a habitat for other creatures, and it would be a shortsighted shame if one species’ habitat was destroyed so another could thrive.

Breaching the causeway at Bateman Island has major ramifications to wildlife and people. State officials will have to be prepared to alleviate any negative consequences that might occur if they end up going through with such a drastic plan.

This story was originally published July 6, 2016 at 5:03 AM with the headline "Our Voice: State responsible for mitigation if Bateman causeway breached."