Nissen In-Place Storage with Slurry Wall

Project Location: Greeley, Colorado

Project Description:

This water storage facility utilized an approved gravel mining site in stages. Several water storage techniques were used to achieve below ground unmined storage vessels that could be utilized for water storage years ahead of the actual need to mine the gravel. This reservoir has the capacity to hold approximately 2,700 acre feet of water upon completion of mining the gravel.

In the interim, utilizing the State of Colorado Engineer leak test approved 10,532 LF soil-bentonite design-build cutoff wall vessels (slurry wall); the Nissen Storage Vessel was designed and built to accommodate in-situ storage (storage filling the voids throughout the gravel lenses). This was accomplished with an inlet structure diverting water off an existing irrigation canal, building a series of recharge ponds with "check" structures, and 3 wet wells with a vertical depth of 65 FT and a vertical pump with 75HP and a 30" HDPE conveyance pipe to an outlet structure. All of this allows water to discharge directly into the South Platte River.

This project was built in stages with multiple municipalities involved to assure compliance with all local, state and federal laws and to meet the needs of the end user.