City Lake Dam Construction Project

Financing has been obtained and sealed bids were opened November 7, 2018 with the contract awarded to the lowest bidder - Kirkland Construction, Rye Colorado (subject to approval by Council on November 20th).

After a contract has been approved by City Council (November 20, 2018 meeting) and signed, the City will completely drain the reservoir and begin drawing water from Horseshoe Reservoir for treatment at the City Water Treatment Plant.

Construction Management Consultant - RJH Engineering

On December 18, 2018 City Council approved a Professional Services Agreement with our consultant RJH Engineering to provide engineering observation, field engineering, and materials testing on site.

Kirkland Construction is also on site and the Dam Reconstruction Project is underway!

Progress Update - January 18, 2019

• City Lake has been drained.
• Water is being pumped from Horseshoe Reservoir directly to the treatment plant.
• Work on a bypass line is underway to feed the treatment plant and once completed there will no longer be a need pump water.
• Deconstruction of the existing dam is underway and excavation is proceeding on schedule.

Once these steps are complete the dam will be rebuilt, a new intake for the treatment plant will be installed and the dam will be refilled.

Progress Update - March 12, 2019

Progress Update - April 9, 2019

• Removal of soft material is underway.
• Excavation is being done down to bedrock.
• Bedrock is being exposed and cleaned.
• A sand chimney is being constructed at the center of the dam.
• Basalt for rip-rap is being imported.

Progress Update - April 26, 2019

• Progress is being made as seen in the busy construction overview photo.
• Both sandy material and clay-rich materials are required for construction of the dam.
• The fill material is being carfully placed adjacent to the sand chimney.
• The fill material is then blended and compacted to specification under the watchful eye of a geologist.

Progress Update - May 15, 2019

• The elevation of the dam embankments varies from "complete" to "eight feet short of top".
• On good production days, the dam height is being increased at a rate of one foot per day.
• Two manholes have been installed.
• Toe drain piping is being installed along with surrounding drainage gravel.

Progress Update - June 7, 2019

Bulldozer on Embankment

The Dam embankment rises daily.

The top of the embankment shown here is five feet short of the finished elevation.

Pipe has Arrived

Eighteen inch diameter steel pipe has arrived.

It will be encased in concrete and will conduct water from the reservoir to the Water Treatment Plant.

Progress Update - June 21, 2019

High density polyethelyene (HDPE) pipe welding machine.

Closeup of HDPE welded joint.

Laying the HDPE pipe. The yellow pipe is the 18" welded steel main input to the water treatment plant. The blue pipe is the outlet for the toe drains.

Progress Update - July10, 2019

Very impressive progress is being made on the City Lake Dam project. On schedule and on budget.

The Rip-Rap is an assembly of three layers. Coarse gravel, small stones and basalt boulders. Rip-Rap stabilizes the earth embankment against erosion by wind and waves.

The concrete foundations provide support for the outlet gates and the spillway.

Progress Update - July19, 2019

The crane pump arrived to pour the second lift at the spillway,

To ensure quality control slump tests are taken. Techs test weight and air content and take sample midway in the pour,

Progress Update - August 9, 2019

Progress is being made on the spillway with the main feed to the treatment plant installed and welded, forms set and poured and the spillway cast,