Clarks Creek Sediment Removal Demonstration
This project included substantial permit submittal and discussions with WDFW to receive the permitted HPA documents during 2013 and 2014. The project is the first in WA State to be permitted for this specific work, and will be monitored and reviewed to provide data back to WDFW for review.
The demonstration project was first proposed to involve a hydraulic dredging process to remove accumulated sediment from a 400-foot section of Clarks Creek. The method is meant to remove sand and smaller-sized particles, leaving cobbles and larger rocks. However, based on site reconnaissance completed once the permits were issued in 2014, it was discovered that a rocky bottom does not exist within at least 6-10 feet of the current sediment bottom.
The purpose of the demonstration project is to evaluate the permitting process and regulatory requirements, determine the effectiveness of the method, determine the underlying condition of the creek bed, determine if cobbles/rocks present, evaluate the depth of accumulated sediment, analyze the environmental and habitat impacts, and monitor the long-term effectiveness of the project including the rate (if any) of sediment loading back into the demonstration area.
The City continues to research, develop, and construct projects that will reduce the sediment loading to Clarks Creek. Several projects are budgeted for 2015 and beyond, with more in the conceptual stage for future development when funding is available. Such projects include:
Requirements imposed by the project permits including the following monitoring activities for the demonstration project: