Final town hall set for Sitka Sedge dike and tidal wetland project
Sitka Sedge State Natural Area. Photo: Unknown author, CC0, via Wikimedia Commons.
A tide gate built in the 1930s near Sand Lake has been failing for years, and the state’s plan to replace it is close to final. The public gets one more chance to ask about it on Nov. 18.
Oregon Parks and Recreation Department and the Tillamook Estuaries Partnership will hold the last town hall for the Sitka Sedge tidal wetland restoration and dike project as a Zoom webinar from 7 to 8 p.m. that Wednesday, according to OPRD’s project page. The agencies say it will be the final town hall for the project. A technical team reviewed the 90% design plans on Nov. 4, and the project went before the Tillamook County Board of Commissioners the same afternoon.
Sitka Sedge State Natural Area is a 389-acre park between Sand Lake and the community of Tierra del Mar, north of Pacific City. It holds ocean beach, dunes, forest, tidal and freshwater marsh and mudflats in a small space, and it is one of the better places on the coast to see that whole sequence on foot.
A dike that holds water in, and fish out
A half-mile dike and tide gate went in during the 1930s to keep tidewater off the land behind it and drain the marsh. The dike also blocked coho, chum, steelhead and coastal cutthroat trout from reaching their historic spawning and rearing water upstream.
Over the last 30 years the tide gate has broken down. OPRD describes it as working like an hourglass now: tide water seeps in slowly, rises to a lower level inside than outside, then drains back out slowly. That’s manageable in normal weather. When a big storm lines up with high tides, water backs up behind the dike and stays high for days. The fast flow through the failing gate is also eroding the dike, and the state expects it to fail eventually if nothing is done.
Any fix has to meet state fish-passage rules. And the people with the most at stake are the homeowners in Tierra del Mar, which sits behind the dike and has worried for years about what changes would mean for flooding and groundwater.
Why the setback dike won out
The state spent 2017 to 2019 modeling the problem. Consultants Pacific Groundwater Group and Environmental Science Associates found that groundwater effects on Tierra del Mar ranged from insignificant to beneficial depending on the design, and that some options would drain stormwater better than the current setup without letting tides reach private property.
In March 2020, after a technical team scored the alternatives, OPRD chose to pursue a setback dike: a new dike built farther back that protects the neighborhood while letting tides return to part of the old marsh. The Tillamook Estuaries Partnership has led the grant-writing and design work since then, though the project stalled from mid-2023 to fall 2024 for lack of money.
The current design would restore fish passage to Reneke and Beltz creeks and reopen 68 acres of formerly diked estuary north of Beltz Creek.
Construction timeline
If permits and funding come through, work would happen over two summers:
- Summer 2027: first phase of the setback dike and the Reneke Creek floodplain. The park stays open.
- Summer 2028: finish the setback dike, remove the old tide gate, open a new breach in the existing dike and install a pedestrian bridge. The park will close for several months during this phase.
A Tillamook County land use application was filed this summer and is under review, and the partners have applied for several grants to cover construction. The schedule depends on both.
Residents who want to attend can register through the Zoom link on the OPRD project page, where the 90% plans, a fact sheet and recordings of past meetings are posted. Questions can also go to OPRD.SitkaSedge@OPRD.oregon.gov.
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