CLIPA White Paper - Lake Maintenance Plan

The CLIPA Capitol Lake maintenance study finds that the “maintenance dredge” activity should begin immediately within the Capitol Lake North basin. A prime location for a sediment “fall-out” pocket is where the current no longer flows, which in this lake/river system is in the center of the North basin.

• Alternatively, the North basin could be completely drained and allowed to sufficiently dry, such that equipment could enter the basin directly for dredging operations.

• A “dewatering staging area” established at the GA acreage located directly west of Marathon Park for future upland distribution;
• Directly loaded into railway cars for overnight dewatering and haul off for landfill caps at various Pacific Northwest locations;
• Transfer the dredging spoils into Percival Cove; or in the southwest corner of the Middle basin where prior dredging spoils were deposited; or contiguous to this area in the southern portion of the Middle basin, to begin creating a wetlands viewing park within the lake. This latter concept likely would require development of predesigned berms at strategic locations. The material would be redistributed into the Middle basin by creating wetland berms, for nature pathways, and additional park area. This set of options eliminates the need for exporting sediment, would have minimal costs, and could be accomplished within a typical “fish-window” timeframe.