Geoscience Reference
In-Depth Information
Figure 16-15.
Early sketch map of Cheyenne Bottoms near Great Bend, central Kansas, United States. The oval
shape of the bottoms is shown in gray. Deception and Blood creeks are the natural tributaries, which have built a
delta complex in the northwestern portion of the bottoms near Hoisington. Elevation contours in feet; 1800 feet is
∼
550 m. Modii ed from Haworth (1897, Fig. 1).
(Zimmerman 1990). The geological origin of the
basin may be connected with deep-seated tec-
tonic movements associated with an ancient
meteorite impact structure in the basement rock
(Merriam 2011), subsurface salt solution and
l owage, as well as suri cial wind and stream
action (Aber and Aber 2009). Mean annual pre-
cipitation for the Cheyenne Bottoms vicinity is
about 65 cm per year, but yearly precipitation
l uctuates greatly from less than 40 cm to more
than 1 m (High Plains Regional Climate Center
2011), which leads to highly variable water con-
ditions. Several major l oods have occurred in
the past century; some of these were severe
enough to transform the bottoms into a large
lake covering more than 80 km
2
. At other times,
during droughts, the bottoms has dried up
completely.
These extreme l uctuations have made the
area subject to water management endeavors
since 1899, when the i rst water diverted from
the Arkansas River was channeled into the
bottoms. The current water-supply scheme was
enacted in the 1950s and substantially enhanced
in the 1990s for the state wildlife area, which
encompasses nearly 20,000 acres (8000 ha). It
involves dams, canals, dikes, and high-capacity
pumps to regulate water levels in several artii -
cial pools (Fig. 16-16). The state wildlife area is
managed primarily for migratory waterfowl and
shorebirds (Penner 2010).
The Nature Conservancy (TNC), on the other
hand, makes no attempt to manipulate water
supplies on its land covering almost 8000 acres
(3200 ha). TNC land is managed for waterfowl
and shorebirds as well as grassland birds
(Penner 2010). Since the 1990s, in fact, TNC
has removed barriers or artii cial controls,
where possible, in order to restore and maintain
natural wetland habitats (see Fig. 13-2). Over-
l ow from TNC land spills into the state wildlife
area pools.
Cheyenne Bottoms has experienced cattail
expansion since the 1970s, which was quite
