C150331 Feasibility Study

• Contract/PO #: C150331
• Contractor Name: North Delta Irrigation Company
• Contract Type: Loan
• Water District: 40
• County: Delta
• Loan Projects - Doc Type: Feasibility Study

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NORTH DELTA IRRIGATION COMPANY (NDIC)
NARRATIVE
TO: Ryan Edwards
From: Lynn French
February 28, 2012
RE: CWCB Loan and Grant Applications.
Background: This project involves the reconstruction of a 1450 foot long irrigation
tunnel located east of Delta, Colorado by sliplining the tunnel with 1500 feet of 54"
HDPE DR 17 fused pipe and construction of 7625 feet of 60" ADS low head irrigation
pipe to be installed in the NDIC open ditch both east and west of the tunnel. All work
will be done in accordance with plans and specs provided by Westwater Engineering
Company. This project became necessary when there was a partial cave in which
stopped water flowing through the tunnel in the end of July 2011. The tunnel and ditch
convey the water right belonging to NDIC out of the Gunnison River in the amount of
49.625 cfs. Approximately 171 water users are adversely affected by this cave in which
has created an emergency situation. Those users east of the tunnel are not affected. The
tunnel was constructed by hand in 1901 through a layer of shale and is long past its useful
life. According to the engineer, Kellie Knowles, it is necessary to pipe the ditch to
achieve maximum efficiency through the tunnel as there is little fall in the total distance
of 9125' that will be piped.
This narrative will address 3 areas:
Availability of water for the 2012 irrigation season.
Bids for the proposed work
Engineering
Availability of water for 2012 irrigation season: Assuming that CWCB
approves the grant and loan requests on March 20, 2012, the reconstruction of the
tunnel and piping the ditch will be completed by June 1, 2012. During the
reconstruction of the tunnel, water will be flowing through the ditch and tunnel.
Cleaning out the tunnel will be done by a directional boring and reaming process
which requires water flowing through the tunnel. After the pipe is pulled through
the tunnel it is necessary to have water flowing through the pipe during the
grouting process so that the pipe will not "float" and will remain on the existing
floor of the tunnel. This entire process will be completed by May 2, 2012. The
piping of the ditch will be completed by June 1, 2012. Water will not be flowing
through the tunnel while the pipe is being installed in the open ditch. Thus, water
from another source will be necessary for the month of May, 2012. Attached is a
letter from Stephen Tuck, State Water Commissioner, dated February 27, 2012,
confirming that approximately 40 cfs will be available from Tongue Creek