The Solomon River drains an
area of 6,835 square miles in northwest and north central
Kansas. There were an estimated 39,900 residents in the basin
in the year 2000, and the population is projected to be 34,100
by the year 2040. The basin is unique in that all of its
drainage area is within Kansas. From the headwaters of the North
and South Forks of the Solomon near the Sherman-Thomas county
line, the basin extends eastward to the confluence of the
Solomon with the Smoky Hill River in Dickinson County. Three
U.S. Bureau of Reclamation dam/reservoir projects regulate
streamflow in the Solomon Basin. These are Kirwin (North Fork),
Webster (South Fork) and Glen Elder/Waconda at the confluence of
North and South Forks Solomon River.
Surface elevations in the
Solomon River Basin decline from about 3,300 feet in the western
North Fork drainage to 1,150 feet at the confluence with the
Smoky Hill River. Average annual total precipitation varies
from 18 - 30 inches, west to east, while average annual surface
runoff increases from 0.1 inches in the west to 4.0 inches in
the east.
Ground water is the principal water supply source in the Solomon
Basin, accounting for about 93 percent of reported water use
(1997 water use data). Irrigation is the predominant use of
water. Principal aquifers include the High Plains (Ogallala) in
the west, the Dakota in the east and alluvial/terrace deposits
along major streams. A portion of the basin lies within
Northwest Kansas Groundwater Management District No. 4. Two
irrigation districts (Kirwin and Webster) rely upon releases
from their namesake reservoirs for water supplies. The State of
Kansas has not purchased any water supply storage in the federal
reservoirs in the basin. Likewise, no multipurpose small lakes
have been developed. One watershed district (Salt Creek
Watershed Joint District No. 46) has been organized in the
basin.