Algae bloom in Capitol Lake

What happens if we don’t restore the Deschutes River Estuary?

In last week’s blog post on the Top 10 Personal Reasons to Restore the Deschutes River Estuary we talked about what drives the DERT team to restore the estuary. But what happens if we don’t restore the estuary? Why is there a sense of urgency to this process? Why do we need to restore the estuary?

If you missed last week’s blog post sign up for our newsletter to get once a week emails about our blog posts, Facebook Live chats and events. Now lets dive into those questions.

Capitol Lake is actually a river

Capitol Lake is not really a lake – it is the estuary of the Deschutes River which has been dammed creating a shallow reservoir. This causes problems because like all rivers the Deschutes is carrying large amounts of sediment (gravel, silt, clay, etc.) transported from its watershed.

Before the dam was put in this sediment built features such as beaches in the estuary and in Budd Inlet. Now the sediment is trapped behind the dam where it is steadily filling up Capitol Lake.

Overtime this will turn Capitol Lake into a swamp.

All sides agree that this is not the future we want. So what about dredging – can’t we just dredge the sediment out and keep the lake?

Dredging Capitol Lake is not an option

Lake supporters often bring up the idea that we should just dredge the lake to keep it as a lake. This statement ignores the facts surrounding this option.

There is a reason why no dredging has been done since 1986.

Dredging has no environmental benefits. Yup, you are reading that correctly – there is no environmental benefit to dredging the lake.

With over 35,000 cubic feet of sediment transported into Capitol Lake annually dredging would be a never ending process that would at best just keep Capitol Lake from turning into a swamp.

The water quality issues in Capitol Lake and Budd Inlet will continue as long as the 5th Avenue Dam remains. Dredging might keep a reflecting pond but it would do nothing to deal with the problems caused by damming a river.

Capitol Lake negatively impacts water quality

By not restoring the Deschutes River Estuary we are choosing to keep the single largest factor negatively impacting water quality in Budd Inlet.


“The Capitol Lake dam causes the largest negative impact on dissolved oxygen of any activity evaluated due to the dam’s combined effects of changing circulation as well as nitrogen and carbon loads”- Department of Ecology 2015 Study


By keeping the 5th Ave dam in place and not restoring the Deschutes River Estuary we are choosing to ignore the science and value a reflecting pond over the water quality of Budd Inlet.

Remove the 5th Ave Dam and restore the Deschutes River Estuary


Capitol Lake is not a healthy environment and we are suffering the consequences of the choice to dam the Deschutes River. If we want to have a healthy environment and vibrant community we need to restore the Deschutes River Estuary.

Watch our Facebook Live chat where we discussed these issues and make sure to subscribe to our newsletter to find out about future blog posts, Facebook Live chats, and upcoming events. We need your help to restore the Deschutes River Estuary!

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