Greenleaf Creek Unnamed Tributary AOP Enhancement

The Greenleaf Creek Unnamed Tributary AOP Enhancement project is located in the Greenleaf Creek/Lake Creek sixth-field HUC 171002060603, in the Lake Creek basin. The Greenleaf Creek Unnamed Tributary flows from its headwaters through Federal forest and private timberland before entering a mix of rural residential and agricultural properties in its lower reach, near the confluence of Greenleaf Creek and Lake Creek. The Strategic Action Plan for Coho Salmon Recovery for the Siuslaw River lists longitudinal connectivity as a key ecological attribute (KEA) and states that “inadequate culverts in tributaries […] often restrict access for both adult and juvenile coho to prime spawning and rearing habitat areas” and this project would support the Siuslaw Coho Partnership’s goal of “upgrading working lands and infrastructure to improve water quality and increase habitat availability”.
The work proposed in the project would address a high-priority fish passage barrier on public lands on an Unnamed Tributary to Greenleaf Creek at the Unnamed Tributary/Greenleaf Creek Road road-stream crossing. The proposed new AOP structure, which has been designed by a private Consultant and subsequently reviewed and approved by BLM engineers and ODFW fisheries biologists, meets ARBO II standards and is sized at 1.5 ACW. The newly constructed streambed through the culvert was designed using stream simulation techniques detailed in the USFS Guide to Stream Simulation.
Project Partners include the Siuslaw Watershed Council, Bureau of Land Management, and the Oregon Department of Fish and Wildlife. The SWC and BLM will cooperatively raise funds and manage the technical details of the project and provide construction oversight. The SWC will be responsible for all project procurement and bid/contract documents. The BLM will permit the project under ARBO II and utilize programmatic pathways for removal/fill reporting.

The goal of the Greenleaf Creek Unnamed Tributary AOP Enhancement project is to improve the quantity and quality of spawning and rearing habitat for OC Coho salmon by replacing an undersized and perched culvert at a road-stream crossing with an appropriately sized and installed structure, as well as improving instream conditions through the input of large wood. This project will benefit salmonids by improving longitudinal connectivity to Essential Salmonid Habitat (ODFW Fish Passage GIS layer) by removing a relic fish passage barrier and will benefit salmonid habitat by restoring natural habitat forming processes associated with large wood presence in streams, such as pool creation and gravel aggradation/sorting. This project would help address two of the primary limiting factors identified in the Siuslaw Coho Partnerships Strategic Action Plan for Coho Salmon: 1) lack of instream complexity 2) limited longitudinal connectivity due to historic road building practices.