locations

Location

Lyman, SC

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P&J Role

Prime Contractor

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Completion Date

May 2023

Project Description

This project consisted of the demolition and construction of a new reinforced concrete flume spillway to replace one that failed during a storm event in February 2020. The existing outlet structure was also upgraded to make it more resilient and effective for the owner. 

Project Highlights

18,000 CY

of common excavation

40,000 CY

of rock excavation

2,000 CY

of dental concrete

312

rock anchors

5,000 CY

of cast-in-place concrete

3,000 CY

of riprap

2000 LF

of underdrain

1

slide gate and stem guide replacement

P&J’S CONTRIBUTION 

P&J demolished and replaced the reinforced concrete flume spillway, including structural slabs, 20’ walls, an underdrain system, rock anchors, vertical drains, and rock excavation. Upgrades to the existing outlet structure consisted of a new slide gate, new pedestrian bridge, and instruments and controls. P&J was also responsible for improving access roads and the stream channel, installing riprap along the bank, final grading, and seeding. 

CHALLENGES & SOLUTIONS 

During this project, work was performed in an existing stream. P&J constructed a concrete cofferdam and installed it downstream of the work area to protect it. Storm events throughout the project also created fluctuating water levels. P&J worked closely with the owner to maintain a lower lake level to have extra storage in the lake for any storm event. A siphon system consisting of 13 – 24” HDPE pipes was installed to aid in controlling the lake level.