DSJ FS_1-25-06

• Year: 2006
• Title: Dolores/San Juan/San Miguel Basin Fact Sheet
• CWCB Section: Water Supply Planning
• Author: CWCB
• Description: Dolores/San Juan/San Miguel Basin Fact Sheet
• Publications - Doc Type: Basin Fact Sheets

Dolores/San Juan/
San Miguel Basin
Growth

The Dolores/San Juan/San
Miguel Basin is comprised of
all or part of seven counties.
Changes in population from
2000 to 2030, including
percent annual growth rate
on a county level, are shown
in the table here. During that
time, the population in the
basin is expected to grow by
80,700 people, or 89 percent.

Dolores/San Juan/San Miguel Basin Population Projections

(continued from page I)

Increase in Percent Percent
Population Change Annual
2000 2030 2000 to 2000 to Growth
County Population Population 2030 2030 Rate
Archuleta 10,000 27,000 17,000 170 3.4
Dolores I,SOO 2,SOO 1,000 56 1.5
La Plata 44,600 SO,600 36,000 SI 2.0
Montezuma 23,900 40,100 16,200 6S 1.7
Montrose 3,400 6,SOO 3,400 100 2.3
San Juan 500 700 200 40 1.1
San Miguel 6,700 13,600 6,900 103 2.4
TOTAL 90,900 171 ,600 SO,700 S9 2.1

Elevations in the Dolores Basin range
from about 14,200 feet near the Dolores
River headwaters, to 4, 100 feet at its
confluence with the Colorado River in
Utah. The terrain of the Dolores Basin
consists of high plateaus with deeply
incised canyons and dry arroyos.

Land use in the region is highly variable
and often reflects a conflict between
historic and modern uses, although
three-quarters of the basin consists of
forest and shrubland. Agriculture and
ranching predominate in the lower
elevations of Dolores, San Miguel, and
Montrose Counties as they have for
many generations. Tourism and
recreation have become more prevalent
in the region as the Animas, Piedra,
Dolores, and San Miguel Rivers offer both
fishing and rafting opportunities.
Montezuma and La Plata Counties are
dominated by agriculture, grassland, and
forested land use types.

The Dolores/San Juan/San
Miguel Basin is projected to
increase in municipal and
industrial (M&I) and self-
supplied industrial (SSI)
water demand by 18,800
acre-feet (AF) by 2030. M&I
is defined as all of the water
use of a typical municipal
system, including residential,
commercial, industrial,
irrigation, and firefighting.
Large industrial water users
that have their own water
supplies or lease raw water
from others are described as SSI water users. M&I
and SSI water demand forecasts for the Dolores/San
Juan/San Miguel Basin are shown in the table
above.

Dolores/San Juan/
San Miguel Basin
Water Demands

Dolores/San Juan/San Miguel Basin Demand Projections

Identified
Projected Increase in Gross
2000 Gross 2030 Gross Conservation Gross Demand
Demand Demand Savings Demand Shortfall
Subbasin Designation (AF) (AF) (AF) (AF) (AF)
Archuleta 2,400 6,400 300 3,700 400
Dolores 400 600 - 200 -
La Plata 9,600 IS,OOO 1,100 6,900 1,000
Montezuma 5,SOO 9,700 600 3,300 200
Montrose SOO 5,500 <100 2,SOO 2,100
San Juan 100 200 <100 - -
San Miguel 1,900 4,400 200 1,900 1,200
TOTAL 21,000 44,SOO 2,400 18,800 4,900

Surface Water Diversions in Acre-feet by Use

Dolores/San Juan/
San Miguel River Basin

o Irrigation
. Storage
o Municipal
o Com mercial

Wet and Dry Periods

Every year, there is at least one lOa-year flood
somewhere in the state. Colorado's total estimated
flood losses to date are $4.9 billion. The Dolores/San
Juan/San Miguel Basin's most recent flood event was
Spring of 1993. The estimated total historic flood
damages for this basin are $14.5 million to date.

o Recreation

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The 2000 and 2030 gross demands are also
presented in the table along with the projected
conservation savings. Conservation practices include
ordinances and standards that improve the overall
efficiency of water use, such as installation of low
water-use plumbing fixtures. As the table indicates,
the Dolores/San Juan/San Miguel Basin will need an
additional 18,800 AF to meet the increased demands
of M&I water use. The majority of the demand is
expected to be met through existing supplies and
water rights and through the implementation of
various projects and processes. However, there are
still some anticipated shortfalls expected in certain
portions of the basin. This is also shown in the table.

[!] Aug mentation

-==-

Source: Colorado Division of Water Resources, Cumulative Yearly Statistics of
the Colorado Division of Water Resources, 1999-2004

- -- ~-- -

Dry

Avg

Wet

San Juan River floods
near Pagosa Springs;
Animas River floods
near Durango

Oct 1972
Lightner and Junction
Creeks flood

June 1927
Animas River floods
near Durango

Sept 1970 Spring 1993
Animas River floods May 1984 Mancos River floods
above Durango I Major flood near Mancos

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Source: Colorado Water Conservation Board and Division 7 staff

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Mancos River (photo courlesy of Colorado State Parks)