C150336 Feasibility

• Contract/PO #: CT2015-088
• Contract/PO #: C150336
• Contractor Name: Left Hand Ditch Company
• Contract Type: Loan
• Water District: 5
• County: Boulder
• Loan Projects - Doc Type: Feasibility Study

3. Construction Alternative 2 - Repair with Concrete
This alternative considered the following action to repair and rehabilitate the damaged face of the
dam; 1) removing and stockpiling the existing riprap, 2) borrowing soil from the reservoir bottom
to flatten the existing slope from a 2H:1 V to a 3H:1 V, 3) grading the crest of the dam to a constant
elevation of 5673 feet and placing 4 inches of roadbase on the dam crest for erosion protection, 3)
installing 8" of concrete on the upstream slope face to prevent further erosion due to wave action,
and 5) adjust the height of the intake structure walls to allow for the flattening of the slope.
The complete breakdown of the work proposed and the cost of the work proposed for Alternative 2
for Allen Lake is shown in Table 4.
TABLE 4
ALLEN LAKE REHABILITATION
ALTERNATIVE 2 - REPAIR WITH CONCRETE
ITEM
DESCRIPTION
QUANTITY
UNITS
UNIT
PRICE
AMOUNT
1
Insurance, Bonds
1
L.S.
$ 15,500.00
$ 15,500
2
Mobilization, Demobilization
1
L.S.
$ 30,900.00
$ 30,900
3
1 Surveying Construction Staking
1
Each
I $ 3,500.00
$ 3,500
4
Dewaterin /Erosion Control
20
Days
$ 500.00
$ 10,000
5
Earthwork
Stripping
1
L.S.
$ 1,500.00
$ 1,500
Borrow
500
C.Y.
$ 3.00
$ 1,500
Fill
500
C.Y.
$ 4.00
$ 2,000
6
1 Staff Gage
1
L.S.
$ 5,000.00
$ 5,000
7
Inlet Stucture Walls
18
C.Y.
$ 625.00
$ 11,300
8
Remove & Stockpile & Place EAsting Riprap
3000
Tons 1
$ 12.00
$ 36,000
9
Concrete Facing
1100
C.Y.
$ 625.00
$ 687,500
10
Furnish & Place Class 5 Roadbase
475
Tons
$ 20.00
$ 9,500
11
Place Topsoil & Seeding
1
Acres
$ 2,500.00
TOTAL CONSTRUCTION COST $ 817,000
CONIINGENCY(200/.) $ 164,000
ENGII,�RING /LEGAUSURVEYING $ 164,000
TOTAL 1 $ 1,145,000
Allen Lake and Lake Isabelle — 12.012
Left Hand Ditch Company Page 13