PROJ00060

• Contract/PO #: C153721
• Contractor Name: Lyons, Town of
• Contract Type: Loan
• Water District: 5
• County: Boulder
• Bill Number: SB 96-153
• Loan Projects - Doc Type: Feasibility Study

Pre-Sed floor slope:
Sluiceway floor slope

2%
5%

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LYONS DIVERSION DAM

Desi!!n Criteria

Flow Range past headworks:
Diversion capacity (max):
Pre-Sed velocity:
Pre-Sed sluicing velocity:
Pre-Sed Sluicing flow rate:

0.2 - 2120 cfs
5 cfs
'::;'0.5 fps
2.4 fps
6 cfs

Sluicing Velocity transverse to headgates: 4 fps
Velocity thru headgates (min): 3 fps

Trashrack/Headwall losses:

0.2'

Desi!!n Elevations (relative to survey results)

Diversion Dam Low Flow crest elevation: set at 95.50 (invert of Trapezoidal Flume)
Operating Crest Elevation: 96.00

Head!!ate sill:
Rq'd. gross opening: 5 cfs/3 fps = 1.67 sf
For (2) 2' wide headgates, opening depth = 0.42' (Fr = 0.82 - ok)
Headgate sill elev. = 95.50 - 0.2 - 0.42 = 94.88

Trashrack sill:
T-R El. = Headgate sill elev. - 0.88' = 94.88 - 0.88 = 94.00

Sluice Gate sill:
S-G El. = Trashrack sill elev. - sluiceway floor length x slope =
SIuicegate sill elev. = 94.00 - (12 x 0.05) = 93.40

Pre-Sed Channel [(2) x 3' wide]:
Flow area = Q/V = 5/0.5 = 10 sf
Flow Depth = 10 sf 1 6'total width = 1.67'
Floor Elevation (upstream) = div. pool elev. - losses - channel flow depth
Upstream floor e1ev. = 95.5 - 0.2 - 1.67 = 93.6
Floor Elevation (downstream) = upstream floor elcv. - channel length x slope
Downstream floor elev. = 93.6 - (50 x 0.02) = 92.6
Sluice hopper invert elev. (1.0' dia. pipe) = 92.6 - 1.0 = 91.6