FLOOD06355

• County: Sedgwick
• Community: Ovid
• Basin: South Platte
• Title: Flood Plain Information Report Town of Ovid
• Date: 3/1/2000
• Prepared For: Ovid
• Prepared By: CWCB
• Floodplain - Doc Type: Floodplain Report/Masterplan

.

.

.

Ovid, but long-time residents in Ovid have no recollection of disastrous flooding along Lodgepole
Creek.

Previous Studies
The US, Army Corps of Engineers completed a report entitled "Special Flood Hazard Information
Report, South Platte River, Volume ill, Logan-Sedgwick County, Colorado" dated June 1977, The
initial publication ofregulatory flood hazards in Ovid occurred on November 15, 1974 which was
later revised by the FHBM dated November 21, 1978, There have been no revisions to the FHBM
since that time,

Community Response to the CWCS Desil!nation and Approval Process
A letter from the CWCB was transmitted to Town of Ovid regarding the Board's proposed action
for designation and approval of the Ovid FHBM, CWCB staff then visited the community to meet
with local officials, discuss floodplain issues, conduct a site inspection, and obtain field survey data
for Lodgepole Creek. The Town was receptive to the Board's proposed designation action, and
provided verbal consent for the CWCB to review, designate and approve the floodplain information
currently available to the community,

ENGINEERING METHODS

Hvdrolol!ic Analvsis
Hydrologic information used for the FHBM floodplain delineations in Ovid is not available or was
not documented by the Federal Insurance Administration, However, the Corps of Engineers for the
South Platte River developed acceptable hydrologic information, This information can be found in
the Corps report dated June 1977 as previously referenced,

For Lodgepole Creek, CWCB staff researched available streamgage information in the region and
performed limited hydrologic analyses to estimate a 100-year peak flow at Ovid, A flood frequency
analysis was performed on annual peak flow records at the Lodgepole Creek gage at Ralton,
Nebraska, The gage has 30 years of record, intermittently between 1931 and 1979, The flood of
record (4,560 cfs) was recorded on August 15, 1968, The drainage area at the gage is 3,307 square
miles, and the elevation is 3,590 feet The 100-year computed peak flow for Lodgepole Creek at
Ralton, Nebraska is approximately 3,500 cfs.

In addition to the flood frequency analysis, CWCB investigated the use of regional regression
equations published by the CWCB and the USGS, However, both methodologies are not
applicable to Lodgepole Creek due to restrictions in the maximum drainage area size, A rainfall-
runoff model has not been developed for this watershed,

The CWCB recommends that a 100-year peak flow of 3,500 cfs be used for drainage studies on
Lodgepole Creek at Ovid until more detailed hydrology can be provided in the future,

3