Irrigated agriculture is in decline in Colorado’s South Platte River Basin (SPRB). Land use is transitioning from farms to urban, suburban and industrial areas. Irrigation water rights are being transferred from agricultural to municipal and industrial uses to support growing urban water demand. The SPRB has been the epicenter of Colorado’s urban growth and thus, agricultural to urban water right transfers, which has reduced the amount of irrigated area in the river basin and is changing Colorado’s rural landscape. Colorado’s Statewide Water Supply Initiative (2011) estimated that the current population in the SPRB may increase from 3.5 million to 6.6 million in 2050. To meet increased municipal and industrial water demands, an additional 510,000 acre-feet per year will likely be needed in the SPRB resulting in a projected reduction of up to 267,000 acres of irrigated agricultural lands. While future loss in irrigated agriculture has been projected, analyses of past changes in irrigation in the SPRB have been limited. Using irrigated lands data from the Colorado's Decision Support Systems we examined how irrigated acreage has changed from 1956 to 2005. In 1956, the SPRB was home to approximately 982,000 acres of irrigated agricultural lands. By 2005, over 150,000 acres of irrigated agriculture have been lost and much was the result of agricultural to urban water rights transfers and changes in land use. What will the SPRB look like in the coming decades?"

1. Changes in Agricultural Irrigation in the South Platte River Basin, Colorado
1956 - 2005
Irrigated agriculture is in decline in Colorado’s South
Platte River Basin (SPRB). Land use is transitioning
from farms to urban, suburban and industrial areas.
Irrigation water rights are being transferred from
agricultural to municipal and industrial uses to
support growing urban water demand. The SPRB has
been the epicenter of Colorado’s urban growth and
agricultural to urban water right transfers, which has
reduced the amount of irrigated agricultural land in
the river basin.
Colorado’s Statewide Water Supply Initiative (SWSI)
estimated that the current population in the SPRB is
prior to any significant change of use (i.e. “dry-up”)
of irrigation water rights, the SPRB contained
~984,000 acres of irrigated agricultural lands.
Irrigated acreage increased to ~1,018,000 acres from
1950 to 1976 as many new agricultural wells were
drilled. By 1987, substantial agricultural to
municipal water transfers reduced irrigated area to
~989,000 acres with a concentration of dry-up in
Park County. Agricultural to municipal transfers
continued to reduce irrigated area through 2001.
Between 2001 and 2005, ~80,000 acres of
agricultural land were removed from irrigation, in
part due to wide-spread administration of junior
References:
Colorado’s Decision Support Systems. 2013. Geographic Information System Data. Retrieved July 2013 from http://cdss.state.co.us
Colorado Water Conservation Board. 2011. Colorado’s Statewide Water Supply Initiative 2010. CDM, Denver, Colorado.
likely to increase from 3.5 million to 6.6 million by
2050. To meet increased municipal and industrial
water demands, SWSI projects that an additional
510,000 acre-feet per year may be needed in the
over-appropriated SPRB where water demand
currently exceeds supply. As a result, SWSI projects
that up to 267,000 acres of agricultural lands may be
removed from production by 2050 to meet the needs
of the growing population.
Using irrigated lands data from Colorado’s Division
of Water Resources we examined how irrigated
acreage has changed from 1956 to 2005. In 1956,
well water rights, particularly in Weld County.
By 2005, total irrigated area had dropped to ~833,000
acres, a reduction of over 150,000 acres (~15%) since
1956, and mainly the result of agricultural to urban
water rights transfers and changes in land use. The
projected conversion of agricultural land over the
next 40 years will more than double the amount of
land that has already been taken out of irrigation
during the past 55 years.
Joel G. Murray, GISP
&
Dan O. Niemela, P.G.
333 W. Hampden Ave.
Suite 1050
Englewood, CO 80110
303.806.8952 | www.bbawater.com