PROJ00518

• Contract/PO #: C153484
• Contractor Name: San Luis Valley Water Conservation District
• Contract Type: Grant
• Water District: 0
• County: Rio Grande
• Bill Number: FSG
• Loan Projects - Doc Type: Feasibility Study

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that it might not be economically reached by the dam). Previous plans for the dam

have called for a rolled earth-fill and rock-fill dam.

1.3.3 Rio Grande Mainstem Potential Reservoir Sites

Three potential reservoir sites on the Rio Grande from Goose Creek to South Fork

were visually identified using USGS county maps at a scale of 1:50,000. These

three candidates are labeled starting with the most downstream site as Rio Grande

1 (RGl), Rio Grande 2 (RG2), and Rio Grande 3 (RG3). Figure 1-2 shows the general

location of the sites. Selected characteristics of a potential 500,000 acre-foot

reservoir at each site are given in Table 1-3 to allow comparisons between the

sites.

Table 1-3
Potential Rio Grande Mainstem Reservoir Characteristics

Dam location (section,twn,rng)........
Storage capacity (af).................
Top of Dam elevation (ft,msl).........
Dam crest length (ft).................
Dam height (ft above river)...........
Surface area (acres)..................
Reservoir length (miles)..............
Drainage area (square miles)....... ...
Est. Mean Annual Runoff (1948-85,af)..

RGl
29,40N,3E
500,000
8,500
3,160
300
4,100
15
925
448,100

RG2
19,40N,3E
500,000
8,555
2,660
315
4,470
16
905
442,000

RG3
4,40N,2E
500,000
8,630
1,670
300
5,030
12
894
439,000

Investigations of water available to a new reservoir should consider both physical

and legal constraints.

It is worthwhile then to explore the three mainstem

reservoir candidates for significant differences in major water rights or major
inflows.

It is estimated that the unit runoff from the tributary area between RGl and RG3

approximates 300 acre-feet per square mile. This is less than the unit runoff of

approximately 480 acre-feet per square mile indicated by the gaging stations of the

Rio Grande and Goose Creek near Wagon Wheel Gap and reflects the lesser mean

altitude of the contributing area between RGl and RG3. Using 300 acre-feet of

runoff per square mile, it is estimated that the area between the RGl and RG2 sites

contributes approximately 6,000 af annually and the area between the RG2 and RG3

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