Weyerhaeuser mill site options for the future
October 3, 2008 · Updated 2:41 AM
As Weyerhaeuser considers its short term options for the mill site, the community has to come to grips with the fact that the long- term viability of the mill site is at stake.
The best way to attract new industrial businesses to the mill site is to eliminate the flood plain designation by constructing a protective dike separating the approximately 240 acres of buildable industrial land from the pond and the adjacent drainage areas, which total ap
Here's my plan for the long-term viability of the industrial property. It must be protected from flooding. This can be accomplished by:
Abandon the Mill Pond Road and extend Snoqualmie Parkway into the mill site. The entire road will be abandoned from the entry point into the mill site on the southwest corner of the Weyerhaeuser property then proceeding easterly to a point ending at Reinig Road. Return the abandoned easement to its natural grade by removing the road surface and all fill material and drainage structures.
The county has a 60-foot-wide easement (not a right of way) from Weyerhaeuser to occupy the Mill Pond Road. That easement will be terminated by agreement at a point connecting with Meadowbrook Bridge. A new easement will be granted by Weyerhaeuser, creating an extension of the Snoqualmie Parkway into the mill site. Additionally, the Mill Pond Road segment from Reinig Road to Meadowbrook Bridge could be re-established as an elevated road.
A vital component of the Snoqualmie Parkway extension into the mill site is that the road bed must be elevated above the floodway. There must be no drainage from the pond side of the parkway into the industrial side of the parkway. Drainage from the industrial side will be engineered for on-site containment and any necessary toxic treatment before being allowed into the sewer system.
Return the sort yard to its natural contours. Once the Mill Pond Road is removed, work must proceed to return the sort yard to its natural grade. This includes the total removal of the berm and its remnants. It's possible that the road bed material salvaged from Mill Pond Road and the sort yard could be incorporated into the new Snoqualmie Parkway extension. The overall objective is to re-establish an unimpeded flood plain/floodway, which will function as a natural drainage zone during periods of flooding from the pond.
I wrote earlier that flood waters from the pond became trapped behind the berm, and when the rising volume has nowhere to go, the incoming water begins to back up toward the Snoqualmie River. A major benefit to this plan will be that flood waters would not have that berm as an obstacle and will empty out into the river, downstream from the downtown district.
Convert the pond into a flood control system. Very few people remember when Borst Lake was only about 10 to 15 surface acres when it was being used by the Snoqualmie Falls Lumber Co. for log storage. The lake occupied the lower part of the current pond. About 10 years after the Weyerhaeuser Timber Co. bought the mill from the Fisher family, they began an immense dredging project, creating the circular pond as it is today. Much of the dredging spoils were either dumped onto the island in the middle of the pond, or hauled by rail and dumped elsewhere.
The maximum depth of the pond is about 20 feet. The pond level is held steady by a weir that is near the Mill Pond Road. The pond levels can be manipulated by adjusting the weir. Sinkers (i.e., water-laden logs) were periodically removed from the bottom of the pond. After the sawmill was closed, the last of the sinkers were salvaged. Water quality has improved since the pond stopped being used for industrial purposes.
A significant element of my concept is to use the pond and the surrounding area as a flood management zone. A structural part to this plan is the construction of a flood spillway that would carry flood waters from the mill pond and discharge them back into the Snoqualmie River at a point downriver from the Burlington Northern Railroad trestle, which was recently demolished.
As a flood management zone, the pond would come under the authority of the King County Flood Control Division, unless or until the city annexes the mill site. During periods of anticipated flooding, the water level of the mill pond could be lowered in advance of a flood event. The pond would accept the flood water and reduce the immediate impact of higher volumes downstream. As the mill pond reached its peak level, the overflows would be discharged into the river from the spillway.
This spillway may provide a small margin of relief, but it will help the downtown district to some extent, which is better than nothing.
During the mid 1980s, the Army Corps of Engineers proposed a flood reduction project that followed the logic of taking the north bank of the river and grading off an estimated 700,000 cubic yards of material. This stream embankment project would allow the river to rise in a broader channel adjacent to the downtown district; it would thereby pass a greater volume of water downstream and reduce flooding. The pond area includes all of Weyerhaeuser's land down to the river.
Dick Ryon is a former land use manager for the Weyerhaeuser Cascade Operations at Snoqualmie. To contact Ryon, e-mail RARyon@concast.net.