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Stable Streambank Protects Existing Infrastructure

The Phinney Branch was experiencing significant erosion on the south bank. The bank was approximately six-feet in height with bare soil and was in danger of encroaching upon the fence-line of adjacent property owners. Farnsworth Group was hired to stabilize the bank and protect the existing infrastructure.

Farnsworth Group completed a topographic survey of the stream and vicinity and performed a visual stream assessment. This reach of the Phinney Branch is located within a green linear park in a residential neighborhood. The channel is entrenched but stable within the stream corridor, except for the eroding bank.

To stabilize the bank, Farnsworth Group designed a small bankfull bench on the south bank to slow channel velocity before the water reaches the unstable high bank. The bankfull bench was created with fill dirt, with riprap on the slope, a coir log on the corner of the bench and native plantings on the bench. Two J-Hooks direct flow into the center of the channel and away from the south bank, and a Cross-Vane Weir at the downstream end of the project reach holds the project together and prevents downcutting. All structures are constructed with large boulders.

The result of the project is a stable stream, improved ecological habitat in and around the stream structures, and improved aesthetic value within the green parkway.