FLOOD06827

• County: Logan
• Community: Sterling
• Basin: South Platte
• Title: Pawnee Creek Overflow Interceptor Channel
• Date: 10/1/2001
• Prepared For: Sterling
• Prepared By: ICON Engineering, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

FEDERAL EMERGENCY MANAGEMENT AGENCY
RIVERINE HYDRAULIC ANALYSIS

PUBLIC BURDEN DISCLOSURE NOTICE
Public reporting burden for this form is estimated to average 2.25 hours per response. The burden estimate includes the time for
viewing instructions, searching existing data sources, gathering and maintaining the needed data, and completing and
viewing the form. Send comments regarding the accuracy of the burden estimate and any suggestions for reducing this
burden to: Information Collections Management, Federal Emergency Management Agency, 500 C Street, S,W" Washington DC
20472; and to the Office of Mana ement and Bud et, Pa erwork Reduction Pro'ect (3067-0148), Washin ton, DC 20503,
You ere not required to respond to this collection of information unless a valid OMB Control Number is displayed in the upper right comer of this
form,

O,M,B No, 3067,0148
Expires April 30, 2001

Note: Fill out one form for each f100dina source studied
Community Name: City of Sterlina. Laas" County. Colorado

Flooding Source: Pawnee Creek Overflow

Project Name/ldentifier: Pawnee Creek Overflow lnterceotor Channel

1. REACH TO BE REVISED

Describe the limits of the revision OR submit a copy of the FIRM with the revision area clearly highlighted.
Copy of FIRM(s) attached depicting area of the revision (highlighted, or circled)? IZI Ves

Downstream Limit: {see attached)

Upstream Limit: 5000' West of US Hiohwav 6 on Countv Road #22 1/2
2. MODELS SUBMITTED

for areas which do not have detailed
floodina:
Only the 100'year (Base) flood profile is
required. A hydraulic model is not required
for areas which do not have detailed
flooding; however, BFEs may not be added to
the revised FIRM. If a hydraulic model is
developed for the area, items 3 and 4
described below must be submitted.
If hydraulic models are not developed, hydraulic analyses {including all calculations} for existing or pre-project conditions and
revised or ost- ro"ect conditions must be submitted.
1. DUDlicate Effective Model 0 Natural File Name N/A 0 Floodway File Name N/A
Copies of the hydraulic anatysis used in the effective FIS, referred to as the effective models (10" 50" 100" and 500'year
multi~profile runs and the flood way run) must be obtained and then reproduced on the requester's equipment to produce the
Duplicate Effective model. This is required to assure that the effective models input data has been transferred correctly to the
requester's equipment and to assure that the revised data will be integrated into the effective data to provide a continuous FIS
model upstream and downstream of the revised reach.

Reauirements: for areas which have detailed floodina:
Full input and output listings along with files on diskette for each of the models
listed below (items 1-4) and a summary of the source of input parameters used
in the models must be provided. The summary must include a description of any
changes made from model to model (e.g., Duplicate Effective model to
Corrected Effective model}. At a minimum, the Duplicate Effective (item 1) and
the Revised or Post-Project Conditions (item 4) models must be submitted. See
structions for directions on when other models may be required.

2, Corrected Effective Model 0 Natural File Name N/A 0 Floodway File Name N/A
The Corrected Effective model is the model that corrects any errors that occur in the Duplicate Effective model, adds any
additional cross sections to the Duplicate Effective model, or incorporates more detailed topographic information than that used
in the currently effective model. The Correctly Effective model must not reflect any man-made physical changes since the date
of the effective model. An error could be a technical error in the modeling procedures, or any construction in the floodplain that
occurred prior to the date of the effective model but was not incorporated into the effective model.

3, Existino or Pre,Proiect Conditions Model 0 Natural File Name N/A 0 Ftoodway File Name N/A
The Duplicate Effective model or Corrective Effective model is modified to produce the Existing or Pre~Project Conditions model
to reflect any modifications that have occurred within the floodplain since the date of the Effective model but prior to the
construction of the project for which the revision is being requested. If no modification has occurred since the date of the
effective model, then this model would be identical to the Corrected Effective model or Duplicate Effective model.

4. Revised or Post-Proiect Conditions Model ~ Natural File Name see attached ~ Floodway file Name see attached
The Existing or Pre-Project Conditions model (or Duplicate Effective model or Corrected Effective model, as appropriate) is
revised to reflect revised or post.project conditions. This model must incorporate any physical changes to the floodplain since
the effective model was produced as well as the effects of the project. When the request is for the proposed project this model
ust reflect proposed conditions.

~ Other - Please attach a sheet describing all other models submitted along with the file names. D Natural

o Floodway

PLEASE REFER TO THE INSTRUCTIONS FOR THE APPROPRIATE MAILING ADDRESS

FEMA Form 81-89C

Riverine Hydraulic Analysis Form

MT-2 Form 4 Page 1 of 2