CT2015-151 Final Report

• Contract/PO #: CT2015-151
• Contractor Name: Louden Irrigation Canal
• Contract Type: Loan
• Loan Projects - Doc Type: Report

To:Dale Leach
Date: October 2014
Page 3
• Extend the headgates downstream concrete wall by about 10 feet to replace a washed out
section of the ditch immediately adjacent to the diversion. This area previously was
constructed with large rock and local soils, and should be replaced with concrete grouted
large diameter rock. This area may be filled in with a temporary earth and rock fill and
the concrete work may be done early next spring if necessary.
• Replace rock, gravel, earth fills downstream of the headgate to restore previous ramp to
the top of the diversion structure (about 200-300 cy from surrounding materials). This
work may be done early next spring if necessary.
• The land Owner to the south of the 230 foot washed out section, would like to bring up
the whole area. The ditch company may permanently fill in the area to the south within
100-feet of the centerline of the ditch with Sand Fill. The ditch embankment should be
constructed with concrete blocks with a total fill of about 500 cy per Sketch 1.
• Other washed out sections of ditch embankment as well as low sections which
overtopped should be filled with concrete chucks/rock and earth fill from Donath Lake as
described in the fill section and Sketch 2. The low section of the ditch road as well as the
fill depth should be marked by an Engineer (suggest spray-paint) prior to fill placement.
The amount of fill need for this is about 400cy of material.
• Two sections of the ditch embankment have been washed out requiring about 535 cy of
fill. These sections should be replaced per Sketch 3 using Concrete Chunk/Rock Fill as
described in the fill section. Repairs may be done with an excavator that can reach to the
toe of the embankment or by constructing a temporary ramp down to the toe of the
embankment. In either case fill material should not be end dumped over the eroded
surface but rather carefully place by building the slope back up in 1 foot-compacted lifts
with 4 —foot benches (Sketch 3). Compaction should be done by tamping down each lift
with the excavator bucket or similar method.
• Sand excavated from the ditch may be placed on parts of the ditch road that did not
overtop and are not marked by an Engineer for special fill. These sections of road will be
later stabilized by seeding. The fill should make an even drivable surface.
Early Spring Repairs
• A complete Engineering assessment of the headgate, this may be done this fall if the area
is cleared of debris prior to snowfall.
• Repair and patch any loose concrete work.
• Repair steel gates and mechanisms as needed.
• Grade existing ground to re-create previously existing dirt road roundabout, an area of
about 3,000 square feet.
• Plant tree saplings and an appropriate seed mixture in disturbed areas. Seed mixture
recommendation will be made in the spring.
R:\Louden_Ditch\Louden_Ditch\Products\2013_Flood\Engineenng Rec Letter\10032013_Louden_Ditch_Eng_Assesment_Letter.docx