FLOOD09102

• County: Logan
• Community: Sterling
• Basin: South Patte
• Title: Sterling Flood Control Interceptor Channel Project
• Date: 4/1/2002
• Prepared For: Sterling
• Prepared By: URS
• Floodplain - Doc Type: Project

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SEml.THREE Anected Environments and Environmental Consequences

the farmsteads to Sterling by approximately 2 miles. Since the travel distance would remain
relatively short, the increased distance does not represent a significant impact.

The long-term benefits associated with the proposed action include reduced potential the UPRR
embankment would be washed out during future flood events, and reduced damage to county
roads and Highway 6. Reduced flooding in Sterling would preclude the closure of several flood-
prone city streets.

3,3.3 Alternative 3 - Improve Routing of Pawnee Creek Flood Flows

Vehicular and rail traffic would be affected by this alternative. Traffic on CR 24 would be
rerouted while approximately 1,100 feet ofthe road is regraded. The construction ofthe box
culverts under the UPRR embankment would be done by UPRR and they would be responsible
for rerouting train traffic while the box culverts are being installed. This alternative has been
designed such that flood flows would be allowed to cross Highway 6, CR 24, and CR 39.
During flood events, these roads would be closed to vehicular traffic. Depending on how often
this occurs, this alternative could have a long-term adverse effect on traffic flow. The local
community has stated this effect is acceptable.

The long-term benefits associated with the proposed action include reduced potential the UPRR
embankment would be washed out during future flood events, and reduced potential for damage
to county roads and Highway 6. Reduced flooding in Sterling would preclude the closure of
several flood-prone city streets.

3.4 PUBLIC HEALTH AND SAFETY

Major flooding occurred along the Pawnee Creek in 1935, 1965, 1967, 1990, 1992, and 1997
(ICON 1998), which is a recurrence interval of almost once every 10 years. With high water
levels, sewers have backed up into homes and businesses, exposing people to raw sewage and
associated biological hazards. Flooded streets and roads have also contributed to increased
response time for emergency response vehicles.

3.4.1 Alternative 1 . No Action

With the No Action Alternative, nothing would be done to reduce flooding along Pawnee Creek
and flooding would continue to impact portions of Sterling and Logan County. Response times
of emergency vehicles would continue to be increased where closed or damaged streets, roads,
and highways require these vehicles to use alternate routes.

3,4.2 Alternative 2 . Sterling Flood Control Interceptor Channel (Proposed Action)

With this alternative, the channel would intercept flows up to the lOO-year flood event and
prevent them from entering the City of Sterling and causing flood damage (ICON 2001),
Construction of the bridge over the channel at Highway 6 would allow the highway to remain
open during a 100-year flood. Response times of emergency vehicles in Sterling should not be
increased during future flood events. In addition, with Sterling being protected up to the

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