Site Visit -Mud Mountain Dam Lower Cascade Creek Water Control Facility   5

10/31/2024 Amended to Add Specific Site Visit Instructions

The US Army Corps of Engineers will be hosting a site visit on November 14, 2024, at 10am Pacific Standard Time. The directions are attached. Please contact Jeannette Patton @ jeannette.k.patton@usace.army.mil for information and sign up. More information will be provided soon.

Location: The work is located at the Mud Mountain Dam, located along the White River near Enumclaw Washington. See attached directions.

Project Description

The work includes all work and incidental related work as indicated on the drawings and specifications, to replace the existing MMD Lower Cascade Creek Water Control System with a new Water Control System designed to convey 250 cfs from Lower Cascade Creek to the White River.

a. Install temporary Lower Cascade Creek stream bypass system.

b. Demolish existing Lower Cascade Creek upper Intake Basin.

c. Excavate native soils and replace with fill per the drawings and

specifications.

d. Demolish existing guardrails at the upper and lower switchback.

e. Construct concrete intake and wing wall structures.

f. Construct gravity block wall next to concrete intake structure.

g. Construct concrete outlet basin.

h. Deliver, install and load test pipe support piles.

i. Construct pipe support concrete cap beams

j. Fabricate, deliver and install steel discharge pipe.

k. Install new guardrails at the upper and lower switchback.

l. Remove temporary Lower Cascade Creek stream bypass system.

m. Deliver and install plants and seed at the site, per the drawings and specifications.