WSP06903

• File Number: 8549.600
• Description: Wagon Wheel Gap Reservoir
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 12/1/1941
• Title: Rio Grande Water Conservancy District and Wagon Wheel Gap Reservoir
• Water Supply Pro - Doc Type: Publication

..~
~
~
C)
(.;;)
P

toms, including among- the larger canals,
the Rio" Grande, Farmers Union, Monte
Vista, Commonwealth, Prairie, San Luis and
Costilla.
Only about ten per cent of the irrigation
systems have priorities which have furnish-
ed a satisfactory SUpply during the past
thirty years. The remaining ninety per cent
of the territory has suffered from seasonal
shortages every year, and severe periodical
annual shortag'es.
According to estimates of The Colorado
PlannIng Board, a disinterested State
agency, from a study of wa.ter shortages
compared with crop losses, for the period
1923 to 1934 inclusive, it is fOund that losses
Occurred during these years directly charge-
able to water shortages and lack of regu-
lation, as follows:
1923 ""."__m.... -"""'''.....m-m-$2,800,000
] 924 _'m"..mm _m....._.... 2,300,000
1925 "".m_....... m....___........___.. ],650,000
1926 ......---....__ -----m..m___.._.m...._ ],100,000
1927 ...----......... ...--....--____m_______..____...__. 100.000
] 928 "...m""."'''__''._m_m_.___.... 1,500,000
1929 _m___...__...__...__......__...___....__.._._....... Nominal
1930 ---...--....-..-..-.........----......__m_...__.... 400,000
193] ---...--..-...-.- ......-------..--...--___m___m 3,650,000
]932 ----.--.....-..----.--....-..._____. ........______.._ 2,200,000
1933 ...-..----...-----.......__.______.._ 950.000
1934 ......---............_........__.. ."m........_.... 3,800.000

and average about $2,000,000 PCI' yeaI'. These
~lPars are about equally divided between
\,<,hat mig-ht be called wet ye3l's and dqr
years and furnish a verry g-ood general
average.
Studies show that for evel'y dollar of fann-
er income $7.00 arc added to the national in-
come through channels of trade.
The year of 1929, although not a yeal' of
exceptionally high runoff, fUl'nished the
most ideal supply of any year in the histol'Y
of the country. The supply was distributed
over' the irrigation S(!uson in the most satis-
factory manner to meet the ideal demand
of water users.

Geographical Description
and Geological Factors

The San Luis Valley, constituting the Rio
Grande Valley in Colorado, is a level plain,
bounded on the west by the Continental Di-
vide and on the east by the Sangre de Cristo
Range of mountains, and has an average
altitude of 7500 feet.
The Rio Grande iSsues from the mountain
canyons near the center of the W(~st side of
the valley and flows east to about the cen-
ter. and there turns south and leaves the
valley at the New Mexico state line. The
valley floor contains about 2,000,000 acres
of ,":abte land. Approximately 750.000 acres
of this land is now irrigated - in the neigh-
horhood of 150,000 from the Rio Grande
t50,000 from the iarger tl'ibuatries such as
the Conejas, AJamosa, La Jara and Trin-
chera, nnd the remaind~r from streamR not
at present tributary to the Rio Grande.

---

Almo.t one half of the San- Lui. Vll.1ley
located north of a line generally about one
mile north of the Rio Grande, has no out-
let to the river, and the returns from the
water produced in this area and the DloUn-
tains surrounding on the west, north and
east sides (inclUding about 400,000 acre feet
of water annually diverted into it from the
H.io Grande) other than water consumed
by crop prodUction and vegetative COver ac-
cumulates in the trough or sump area, the
lowest part of the valley in lakes, ponds and
marshes and is lost by evaporation. This
is the water that will be recovered by the
Outlet Drain, Return waters from the re-
mainder of the valley are tributAry to the
rivel' anc;i pass on dawn the river for Use
in New Mexico and Texas.
Annual precipitation On the valley floO!'
averages about nine inches and no crops can
be successfully grown without the aid of
irrigation.
Irrigation water is supplied from rains
and melting snows in the surrounding moun-
tains which reach an elevation of from 10,000
to 14,000 feet. The annual precipitation in
the mountain area is much higher. in some
localities as nluch as sixty inches,
Practically all of the valley floor is under-
laid wi th artesian strata and there are 6.000
or more flowing weBs. most of which al'e
two inches in diameter and from 150 to 2:';0
feet deep, These wells are used pricipaIly
for domestic and stock water purposes. The
water is cold and pure. Some few wells of
larger dimension t.apping flows 800 to 1000
feet below the surface produce as much as
two or three cubic feet per second and are
used in farming operations. Other watel'
bearing strata OCcur generally from 40 to
60 feet below the surface, under pressure in-
sufficient to produce flOWing wells, and
wells tapping this source, 12 to 18 inChes in
diameter, in sOme areas will supply pumping
heads of as much as three and in some in-
stances as much as four cubic feet per sec.
ond_ Between :10.000 and 100,000 acre feet
waR supplif:d by pumping from this source
in the very dry year of 1940, seriously low-
el'ing- the wate!' table in some areas.

ALL IRRIGATED RIVER BASINS FOL-
LOW THE SAM1<~ PATH IN DEVELOP_
M1<;NT, USUAl_LV IN FIVE DISTINCT
AND I,OGICAL STEPS:
1. Construction by the water users them-
selves, of smaIl ditches serving lands immed-
iat.ely along the river and its tributaries.
2. Large canals follow, constructed by
associations, canal companies, irrigation
districts or some such other organization,
gf'nel'ally financed by out.side interests. 3S
a profit making 01' speculative venture, in
anticipation of large profits from future ex-
ploitations of the area served.
3. Construction of small reservoirs, the
full eapaeity of wh ich are filled and emptied
each year, and usually privately financed.
4. Construction of reservoirs of large ca-
pacity to provide wet to dry storage, where~
by surpluses from wet years may be carried

~--...