C150379 Feasibility Study

• Contract/PO #: C150379
• Contractor Name: Wadley Farms Filing No. 3 Homeowner's Association
• Contract Type: Loan
• Water District: 7
• County: Adams
• Loan Projects - Doc Type: Feasibility Study

water use to the point of eliminating all irrigation use. Water demand would therefore be
reduced to just reservoir evaporation. The HOA would take the action of prohibiting all
irrigation use in order to preserve sufficient reservoir levels to maintain water pressure to
water system hydrants in the event of fire in the subdivision. Water pressure is reduced
to the point of jeopardizing water pressure for water system fire hydrants when total
reservoir storage drops below about 30 acre -feet.
Seepage occurs from the Wadley Farms No. ; reservoir feeder ditches and from the
Wadley Reservoirs. the HOA completed significant work in the 1990s to reduce seepage
from the reservoirs, but some still occurs. During the irrigation season, much of the
seepage can be offset by irrigation return flows that enter the reservoir or inflows from
the intermittent North and South Wadley Creeks. Seepage that occurs throughout the
winter will reduce the amount of water available to be carried over for use in the
following year. For purposes of analysis, a 10% shrink for seepage can be placed on the
Wadley Farms No. 3 headgate delivery amounts.
Comparison of Current Water Supplies to Demand
The arnounts calculated for water yields from the HOA's current water rights can be
compared to the Wadley Farms No. 3 water demands in both average and dry years as
shown in Table 6. The current water supply is adequate in average and wet years, but can
cause the reservoirs to be drawn down to the minimum levels needed for fisheries, fire-
fighting supplies and aesthetics even in average years. A bare minimum reservoir pool,
quite possibly inadequate for maintaining fire - fighting protection, can be maintained in
dry years where carryover storage has been minimal if all irrigation use in Wadley Farms
No. is prohibited. The shortage between available annual water deliveries in a dry
year and the maximum water demand in a hot, dry year is 88.8 acre -feet of
shortage. This analysis assumes that future deliveries to the Wadley Farms No. 3
headgate through the Signal Ditch will continue to be similar in amount to past deliveries.
Table 6. Water Supply and Water Demand Comparison
Current Water Su ly
Water Demand
Seepage
Excess/Shortage
(all values
Avg
Dry
Avg
Dry
Avg
Dry
Avg
Dry Year
in ai)
Yr
Year
Yr
Year
Yr
Year
Yr
FHL
shares
54.5
40.8
Irrigation
42.2
0 to
7.9 (w/
total
Reservoir
74.0
2 6. 6
Reservoir
52.8
78.8
irrigation
rights
Evaporation
12.9
6.7
20.6
prohibition)
Annual
Annual
52.8
to 88.8
al
128.5
67.4
95.0
to
shortage)
149.5
Wadley Farms No. 3 Water Supply CWCB Loan Feasibility Study Page 19