By Steven Schauer, Deputy Executive Director and King County Staff
The King County Flood Control District (KCFCD) has been working diligently since its creation in 2007 to safeguard our communities from flooding. The KCFCD, in collaboration with King County as service provider, has spearheaded over 370 capital projects aimed at mitigating the risk of levee and revetment failures. These projects, along with the operation and maintenance of over 500 flood protection facilities, cover 118 linear miles and approximately 800 acres of land crucial for flood mitigation.
While the KCFCD’s weekly blog typically shares information about new and ongoing projects, each month, we will shine a spotlight on a completed project that is quietly doing its job to safeguard our community against the threat of flooding. The project we’re covering this month is the Reinig Road Revetment and Brockway Creek Culvert Replacement Project near the cities of Snoqualmie and North Bend.
Location and Geographical Significance
The Reinig Road Revetment site is situated along the Snoqualmie River at approximately River Mile 43.8. This strategic location is directly across from the confluence with the South Fork Snoqualmie River and about three-quarters of a mile downstream of the North Fork & Middle Fork Snoqualmie River confluence. SE Reinig Road, which runs along the top of the bank adjacent to the project site, plays a vital role in the area’s infrastructure, making the protection of this road and the surrounding properties paramount. The Brockway Creek Culvert Replacement site is located on Brockway Creek, a tributary to the Snoqualmie River about one mile from the Reinig Road Revetment site.
Fun fact: for fans of the television show Twin Peaks, the iconic “Welcome to Twin Peaks” sign was filmed near the location of the Reinig Road Revetment site.
Overview
The Reinig Road Revetment and Brockway Creek Culvert Replacement Projects were completed in 2021 and 2022 respectively, marking a significant effort to rebuild and enhance the Reinig Road Revetment and improve aquatic habitat. This project was crucial in addressing the critical issues of riverbank stability, erosion, and infrastructure protection in the scenic Snoqualmie River Basin, between the communities of Snoqualmie and North Bend.
“The successful completion of the Reinig Road Revetment and Brockway Creek Culvert Replacement Projects represents a significant milestone in the King County Flood Control District’s ongoing efforts to protect our communities and infrastructure from the impacts of flooding,” said Sarah Perry, KCFCD’s Vice Chair and Supervisor for District 3. “By addressing the immediate needs for riverbank stability and erosion control, this project not only safeguards vital infrastructure but also contributes to the long-term resilience and sustainability of the Snoqualmie River and Valley as a whole.”
Project Scope and Improvements
The Reinig Road Revetment was initially constructed in response to a devastating 1959 flood, which is considered the flood of record in the Upper Snoqualmie River Basin. Originally constructed in 1966, the Reinig Road Revetment spans 2,795 feet along the right (north) bank of the Snoqualmie River. Over the decades, high flow events undermined and stripped away portions of the existing revetment, exposing the underlying riverbank material. These damages not only compromised the revetment’s effectiveness but also threatened the stability of SE Reinig Road and other critical infrastructure. This project aimed to repair approximately 775 feet of this damaged structure to ensure long-term protection against river scour and erosion.
A “revetment” refers to a structure or layer built to protect an embankment, shoreline, or riverbank from erosion caused by water flow, waves, or weather. They are commonly used in coastal and riverine environments to stabilize banks and prevent the loss of land and infrastructure. Revetments are designed to absorb and deflect the energy of flowing water, thereby preventing the underlying soil or substrate from being washed away. While revetments have historically been made from materials such as rock, concrete, or geotextiles, the KCFCF, together with King County as service provider, are now using more natural materials, where feasible. For example, by utilizing large wooden structures as part of the revetment, riverbanks can be protected from erosion and habitat can be created for aquatic and riparian restoration.
Project Goals and Objectives
The primary goal of the Reinig Road Revetment and Brockway Creek Culvert Replacement Projects was to restore and enhance the damaged sections of the revetment, ensuring continued flood protection for:
- SE Reinig Road
- Puget Sound Energy’s Power Transmission Lines
- City of Snoqualmie’s Canyon Springs Water Main
- Private Properties
The damaged sections of the revetment were meticulously rebuilt to enhance riverbank stability and increase resilience to future changes in the river channel. Onsite culvert enhancements were undertaken to improve water flow and reduce the risk of blockages.
A series of four log structures were installed to divert high flows away from the riverbank, minimizing erosion and maintaining the integrity of the revetment. Additionally, the project aimed to enhance the aquatic and riparian habitat where possible, contributing to the overall ecological health of the Snoqualmie River.