Despite summer rainfall, the project is on schedule. Work on the north setback levee is proceeding well with completion of this element expected by the end of August. This is one of three setback levees designed to keep daily tides off adjoining farm land that is outside the project area. The approximate 2 ½ miles of these levees are specially designed with a clay-type soil core. Once fully dried and compacted, the core will prevent water infiltration through the levee that might otherwise cause erosion and levee failure. The levee core will be capped with a granular material, also available on site, and graded to a 1/5 slope to minimize erosion during overtopping flood events. The three setback levees are in locations that enable efficient flood discharge over the remainder of the overland flow corridor.
The City of Tillamook, one of the many project partners, is presently contemplating an expansion of a planned parking area on the so-called “containment cell” that is being constructed along the north side of Front Street between Douglas Avenue and an old mill pond channel located west of Cedar Avenue. The proposed revision would accommodate parking for 30 vehicles instead of the 14 contemplated in the initial design. The lot will be available for recreational access to Hoquarten Slough and the surrounding area. A decision by the City on the possible expansion is dependent on a revised bid proposal from the project contractor, Thompson Brothers Excavating, Inc.
In any event, parking atop the containment cell is a creative use for the earthen berm that will be used to encapsulate the slightly contaminated soils that remain on the project site from the two veneer mills that operated from about 1920-1965. The contaminants in the soil consist of remnant motor oil and machine lubricants used at the mills. Although the contamination levels do not pose a risk to humans, the worst of the soils will be transported to a licensed treatment facility in Hillsboro. The lesser contaminants will be encased within the cell and monitored long term. Currently those contaminants are uncontained at the site and pose a risk to the environment.
Further questions may be directed to Project Manager Paul Levesque at 503 842-1809.
With the onset of drier weather the pace of construction has increased. Thompson Brothers Excavating, the prime contractor from Vancouver, Washington, will bring on additional crews and machinery early next week. The Oregon Department of Environmental Quality (DEQ) has given final approval on the cleanup plan for the two former mill sites just north of Front Street in Tillamook. Clearing and grubbing of the mill sites is just about finished but continues elsewhere on the 640 acre project site. The new crew will begin excavation and disposal of contaminated soils as well as removal of the surrounding clean soils that will help with the discharge flood waters.
Approximately 234,000 cubic yards of material will be removed or reused as part of this project. The clean soils will be reused in the construction of setback levees, filling of old drainage ditches or spread out on adjoining farmland where landowners are willing to receive it. The purpose for filling the old ditches is to allow natural drainage channels to reform in a more serpentine manner, thereby producing better salmon habitat. Once the levees surrounding the project area are removed, ancient tidal channels will be reconnected to the rivers and the new tidal channels will become established. This project is expected to create approximately 14 miles of new or reconnected tidal channels that will then serve as critical over-wintering habitat for juvenile coho and other fish. The Oregon Department of Fish and Wildlife has just completed the removal of any remaining salmon in the old ditches so that filling of those ditches may now begin.
Construction of the 2 ½ miles of new setback levees has also started. Core material soils for these levees are being place in 1 foot lifts so they can dry out prior to compacting and covering. These levees are located to protect adjoining farmland from the daily tides that will soon regularly inundate much of the new flood corridor.
A substantial amount of concrete is also being demolished and removed from the old mills and former buildings on the site. Most of this concrete will be placed outside the project area in nearby cow pads that have received permits as elevated refuge islands for cows to escape rising waters during floods.
Despite all the activity since February within the project area, an eagle’s nest adjoining the site is once again home to two young eaglets who don’t seem too eager to leave home as young adults. Regular monitoring of the nest is continuing to occur. Once the eaglets fledge, the work hour restrictions within the buffer area surrounding the nest will be lifted and work can proceed throughout daylight hours as with the remainder of the project area. The eagle’s nest will continue to be protected for future use by the longtime resident nesting parents.
As one of the largest projects of this type ever constructed in the northwest, regular visits are made by state and federal agency staff to monitor progress. Representatives from DEQ were on site last week and officials from the NOAA Fisheries will tour the project next week. For safety reasons, the public is not permitted within the project area until construction is completed.
Construction has begun. On April 27, 2016 a contract was signed with the low bidder Thompson Brothers Excavating, Inc. (TBE) out of Vancouver, Washington in the amount of $5,500,930. TBE mobilized to the site the first week of May. The contractor now has a number of crews working throughout the 640 acre project area.
The construction of the Southern Flow Corridor (SFC) will create a “natural overland floodway” that is currently blocked by numerous levees and dikes. The project will remove these blockages and set back remaining levees in order to provide an unobstructed flow corridor. The net result is that flood levels are reduced over a wide area in the lower Wilson floodplain and even to some degree the lower Trask and Tillamook River systems. Although the SFC was developed as a flood project, it also restores tidal wetland habitats and ecological function as a direct consequence of removing levees and reconnecting 14 miles of ancient channels to the river systems. TBE has completed similar projects along the Columbia River and elsewhere, including work for ODOT.
Demolition has almost been completed at the former farm buildings west of the Hall Slough Bridge on Goodspeed Road. The Tillamook Fire Department conducted a practice burn on the house slated for removal at the end of Goodspeed Rd. TBE crews have started clearing and removing brush and trees that were felled within the project area back in February. This wood debris will be chipped to build temporary construction roads. TBE has also started stripping out top soils along 1.75 miles where set back levees will be constructed.
Approval from the Oregon Department of Environmental Quality is expected the week of June 13-17 on final plans for cleanup of the two former mill sites north of Front St. in the City of Tillamook. Excavation of this area will begin following that approval. For public safety, access onto the entire project site is limited for the duration of the project which is expected to be substantially completed by fall. Regrading of the new setback levees will be conducted, as needed, in summer 2017.
Further questions may be directed to Project Manager Paul Levesque at 503 842-1809.
In early February the SFC Project began pre‐construction activities with tree felling in the Hoquarton and Hall Slough areas west of Highway 101. The SFC project will remove about 8 miles of old levees and dredged material that currently block flood flows to Tillamook Bay. Trees that are growing on top of these levees are being felled before bird nesting begins. The felled trees are being left on‐site until the construction contractor starts major construction work later this spring. Construction work involves the removal of levees and the construction of tidal dikes in order to provide better conveyance of recurrent floodwaters within the Highway 101 Business Corridor. Construction work will last throughout summer 2016; and there will be some followup work in summer 2017.
In addition to mitigating recurrent floodwaters, the SFC Project also provides for wetland
restoration and fish habitat improvement. The SFC Project is the result of many years of public agency and private citizen collaboration.
If you have any questions related to the SFC Project, please contact Paul Levesque, Tillamook County SFC Co‐Project Manager at 503‐842‐1809.
The US Department of Homeland Security’s Federal Emergency Management Agency (FEMA) has published the Southern Flow Corridor Project Record of Decision.
The US Department of Homeland Security’s Federal Emergency Management Agency (FEMA) prepared an environmental impact statement (EIS) to document the benefits and impacts of the proposed SFC project and other alternatives in compliance with the National Environmental Policy Act (NEPA). The comment period on the draft EIS was from May 29, 2015, to July 13, 2015.
The Final EIS has been completed and includes responses to comments collected during the Draft EIS comment period. The Final EIS is available at www.SouthernFlowEIS.org, at locations in both Portland and Tillamook, or by requesting a CD from FEMA. A full list of locations where a hard copy may be reviewed is available at www.SouthernFlowEIS.org.
FEMA will not take action on the Tillamook SFC project until the Record of Decision (ROD) is published. The ROD will not be published until after November 30, 2015.
The US Fish and Wildlife Service (USFWS) has issued the Biological Opinion resultant from their Section 7 consultation pursuant to Section 7 of the Endangered Species Act. The USFWS concludes “that the project as proposed would not jeopardize the continued existence of marbled murrelets”. The full Opinion can be reviewed here.