Squamish-Lillooet Regional District - Catiline Creek Debris Flow Mitigation Project - SLRD Electoral Area C

pre-construction

Lillooet Lake Estates is a 152-lot subdivision with a population of 432 on the northeast side of Lillooet Lake in the traditional territory of the Lil’wat People, located 7 kms south of Hwy 99 on the In-SHUCK-ch FSR in electoral Area C of the SLRD. The project ewill be approx. 1 km in length. The community is built on an alluvial fan. There has been increasing movement of material breaking off the mountain, causing debris flows up to 30,000 cubic meters, which have impacted the safety of residents and buried the only access road for four Nations. The infrastructure will serve the residents of the SLRD & tourists. In 2015, BGC Engineers indicated that the risks are ’unacceptable’. Kerr Wood Leidal (KWL) prepared a design to create a funnel to control up to 100,000 cubic meters (projected 1000 year event) before it enters the community. It will direct material down a channel under a new FSR bridge and into Lillooet Lake. This project is essentially shovel ready. KWL was selected to complete a design. KWL has extensive experience in designing solutions for projects in similar terrain. Preliminary design was completed in Oct. 2016. The plan includes a Risk Analysis, Class C Construction estimates, project budget estimates and future considerations. KWL updated the budget estimate to 2023 dollars. This plan includes the following: Excavate and stabilize a larger creek channel through the community to convey debris flow from fan apex to Lillooet Lake; Supplement creek excavation with berms; Construct fan training berms to reduce risk of Works being outflanked. The excavation project will remove approximately 130,000cbm of material. The Ministry of Forests indicated plans to replace the FSR Bridge to accommodate the wider creek channel and improve the FSR by reducing inclines near community for commercial traffic.