FLOOD09522

• County: Logan
• Community: Sterling, Atwood
• Basin: South Platte
• Title: Pawnee Creek Flood Mitigation, City of Sterling, Town of Atwood and Logan County
• Date: 7/1/1999
• Prepared For: Logan County
• Prepared By: URS Greiner Woodward Clyde
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

I
I
I
I
I
I
I
I
I
I
I
I
I
I I
I
I
I
I
I

SECTION THREE Anected Environments and Environmental Consequences

3.10.3 Vegetation

Vegetation within the project area includes cropland, uplandlriparian areas, planted vegetation
within developed (urban) areas, and planted/native vegetation within transportation corridors.
Cropland within the project area is used to produce sugar beets, alfalfa, and small grains such as
wheat, corn. and soybeans. Upland/riparian area include a variety of vegetation including warm
and cool season grasses, forbs, native shrubs including chokecherry and wild plum, and riparian
species including willows, cottonwoods, reeds, and sedges. Planted vegetation in urban areas
included non-native grasses including bluegrass and brome, and ornamental shrubs and trees.
Vegetation within transportation corridors included native warm and cool season grasses, forbs,
and annual weed species including cheat grass, sunflowers, and ragweed, and an occasional
native tree.

3.10.3.1 Alternative 1 - No Action

The No Action Alternative would not affect vegetation in the project area.

3.10.3.2 Alternative 2 -Improve Routing of Pawnee Creek Flood Flows (Proposed
Action)

With Alternative 2, approximately 45 acres of vegetation would be temporarily disturbed,
including approximately 33 acres of cropland, 10 acres of upland/riparian vegetation, I acre of
urban development, and 3 acres within road and/or railroad ROW. Following construction,
approximately 28 acres of cropland would be returned to crop production and 5 acres would be
occupied by dikes and levees revegetated with native grass species. Disturbed areas within the
developed urban areas, road and railroad ROWs, and upland/riparian vegetation would also be
reseeded with native grass species. Temporary impacts to 45 acres do not represent a significant
impact on vegetation.

3.10.3.3 Alternative 3. Pawnee Creek Overflow Cutoff

With Alternative 3, approximately 41 acres of vegetation would be disturbed temporarily,
including approximately 32 acres cropland, 7 acres of upland/riparian vegetation, less than 1 acre
of urban development, and slightly more than 2 acres within road and/or railroad ROW.
Following construction, approximately 28 acres of cropland would be returned to crop
production, and 4 acres that would be occupied by dikes and levees would be revegetated with
native grass species. Disturbed areas within the developed urban areas, road and railroad ROWs,
and upland/riparian vegetation would also be reseeded with native grass species. Temporary
impacts to 41 acres does not represent a significant impact on vegetation.

3.10.4 Terrestrial Wildlife

Terrestrial wildlife in the project area includes big game and upland game species. The
noncultivated area provides important habitat for big game species, especially deer and upland

3-17