Water Supply and Demand Study 1/13/11

A -LP Water Animas -La Plata Water Marketing Supply and Demand Study Section 3
The SWSI study indicated an annual water supply shortfall for the entire Southwest Basin of 4,900 AF in
2030, including the counties of: Archuleta, Dolores, La Plata, Montezuma, San Juan, San Miguel and a
portion of Montrose. For Archuleta and La Plata counties, the annual water supply shortage in 2030 is
estimated to be 1,400 AF of the 4,900 AF. The SWSI report indicates that this shortage is due largely to
water treatment and transportation /conveyance distribution problems.. As discussed previously, the
study area for this project is only La Plata and Archuleta counties because of the high costs associated
with constructing the infrastructure to move this water.
Table 3 -1 below summarizes the updated gaps from the Draft 2050 Gap Analysis. The gap analysis
identifies 2050 water demands and then subtracts yield of new water supplies created by the Identified
Projects and Processes (IPPs). CWCB also assigned a probability that the IPPs would be completed and
for the Southwest Basin that probability is 75 percent. It should be recognized that while this analysis
indicates a 4,000 AF gap in future supply, the estimated success rate could fall short of the current 75
percent, leaving a significant demand that could exceed even the State's allocation of A -LP water.
Gape (Assumes only 75%
j New Water Supply New Water Supply Yield Implementing New
Yield' (AF/YR) (AF/YR) Water Supplies)
Increase in Demands (AF/YR) (Assuming 100% Success) (Assuming 75% Success) ? (AF/YR)
Low Med High Low Med High Low Med High Low Med High
Archuleta 3,500 i 4,000 4,600 1 3,300 3,800 4,400 2,500 2,900 31300 j 1,000 11100 i 1,300
La Plata 6,800 8,600 10,800 6,400 8,200 10,300 4,80 6,100 7,7000 1 2,00 2,500 3,10
- -- — f - - -- 1 -- -� - - -- - -- - --
1 New water supply are defined as IPPs in SWSL
s Gap = Future Demand Estimate - 75 percent of New Water Supply Estimate
3 Data in this table are from: CWCB, September 2010, Draft 2050 Municipal and Industrial Gap Analysis
Identified Water Supply Projects (Column 2 in Table 3 -3) i.e. IPPs include:
• Agricultural water transfers
• Reuse of existing fully consumable supplies
• Growth into existing supplies
• Regional in -basin projects
• New transbasin projects
• Firming in -basin water rights
• Firming transbasin water rights
For the Southwest Basin, planned water supply projects are estimated to exceed 2050 net new water
demands. However, there may be a problem in distributing this water to unincorporated areas because
the water treatment and infrastructure required to meet these demands may be cost prohibitive without
significant outside funding assistance.
3.2.2 Potential to Serve Other Municipal and Industrial Demands Through Exchange
The objective of this section is to investigate the potential for using the State's water to serve municipal
and industrial demands by exchange thereby enlarging the area served by the A -LP project without
constructing costly pumping stations and pipelines to convey the water (See Figure 3.2.2).
The concept of an exchange of the State's A -LP Project water involves:
3 -3
FINAL ALP Report _ 1_13_11_LL.docx