Requests for Proposals-Consulting Services: Interior Drainage Study

Location:	South Dakota
Posted:	Feb 27, 2026
Due:	Mar 13, 2026
Agency:	City of Aberdeen
Type of Government:	State & Local
Category:	R - Professional, Administrative and Management Support Services
Publication URL:	To access bid details, please log in.

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City of Aberdeen

Engineering

123 South Lincoln Street

Aberdeen, SD 57401

(605)-626-7011

REQUEST FOR PROPOSALS: CONSULTING SERVICES

INTERIOR DRAINAGE STUDY

The City of Aberdeen, South Dakota City Council is seeking proposals from qualified Firms, to provide

Complete Services for the comprehensive study of the City’s drainage system.

The Consultant chosen for this project will be qualified in Hydrologic and Hydraulic analysis to provide

comparisons with the current drainage system and areas of improvement that will enhance the City’s flood

management system.

Qualified firms (including DBE/WBE/MBE firms) interested in being considered for the project are

encouraged to contact:

Stuart Nelson, PE, CFM

Public Works Director/City Engineer

City of Aberdeen

123 South Lincoln Street

Aberdeen, SD 57401

(605)-626-7011

For more information, and to receive a copy of the detailed Request for Proposals.

PROJECT GOALS AND HISTORY

Over the past several decades, the City of Aberdeen has worked toward improving its resiliency from the

effects of significant precipitation/runoff events. The community is an NFIP community, creating

safeguards for its residents and visitors such as participating in FEMA’s Community Rating System and

construction of a levee system.

The City of Aberdeen is committed to improving its resilience through this study and will provide this

information to FEMA and the Corps of Engineers in order to complete the next level of Floodplain

mapping.

SCOPE OF WORK TO BE ACCOMPLISHED

Introduction

The City of Aberdeen is seeking to undertake a comprehensive drainage study to better understand and

address the city’s drainage and flood management needs. This study will encompass hydrologic and

hydraulic (H&H) analysis to provide a clear picture of the current drainage system and identify areas for

improvement.

The City is working with FEMA as part of their Map Modernization Program; FEMA has initiated a

countywide Flood Insurance Study (FIS) and Digital Flood Insurance Rate Map (DFIRM) for all

incorporated communities within the County. FEMA has implemented a policy to verify the certification

status of all levees currently depicted on the effective FIRM as providing protection from the base (1%

annual chance) flood. The regulatory requirements for accrediting levees as providing base flood

protection on FIRMs is found in Title 44 of the Code of Federal Regulations, Section 65.10 (44 CFR

65.10) (see Attachment B). These criteria include design criteria (e.g. freeboard, closures, embankment

protection, embankment and foundation stability, settlement, interior drainage), operation, and

maintenance.

Objective

The primary objective is to provide modeling that reflects the effects of City owned retention ponds, storm

sewer, drainage channels, and levee. This modeling will be provided to FEMA so that their flood

remapping is realistic to the actual conditions. The other primary objective is to use this modeling to

justify the recertification of the City Levee to the USACE.

The secondary objective of this comprehensive drainage study is to evaluate the existing drainage

infrastructure, identify deficiencies, and propose actionable solutions to enhance the city's flood

management capability. This will also facilitate better communication and coordination with FEMA and

the USACE.

Scope of Work

The comprehensive drainage study will cover the following components:

1. Existing Conditions Analysis

GIS Data Assessment:

• Review the existing GIS data, which includes information on storm pipe sizes, manholes, and

inlets.

• Identify gaps in the current data, particularly concerning invert elevations, which are

approximately 20% complete.

• Make necessary assumptions or simplifications to efficiently complete the study.

• Mapping will include all storm pipe sizes 18-inches and larger.

Field Survey:

• Conduct field surveys to fill in missing data, especially for critical areas where invert elevations

are not available.

• Verify the accuracy of existing GIS data and update it as needed.

2. Hydrologic and Hydraulic Modeling

Model Development:

• Develop a hydrologic and hydraulic model of the city’s drainage system. The model will include:

 Storm pipes 18 inches or larger.

 Detention ponds.

 Lift stations & force mains

 Overland conveyance networks such as streets and drainage channels (natural and

manmade).

 Flood control systems.

• Use suitable modeling software, taking into consideration the industry's current standards and

hydraulic models meeting FEMA’s minimum requirements of the NFIP.

Existing Conditions Simulation:

• Simulate existing conditions to identify areas prone to flooding and assess the current system’s

performance.

3. Infrastructure Assessment

Conveyance System Evaluation:

• Assess the capacity and condition of stormwater conveyance systems, including pipes, channels,

and detention ponds.

• Identify deficiencies and prioritize areas requiring upgrades or maintenance.

Levee System Risk Assessment:

• Coordinate with the US Army Corps of Engineers to understand their requirements and timeline

for levee assessments.

• Evaluate the levee systems, focusing on the freeboard requirements at different points, as indicated

by preliminary FEMA results.

4. Coordination with FEMA

Flood Map Review:

• Review the latest effective flood maps from March 2008 and identify discrepancies with the

current conditions.

• Provide input to FEMA’s study contractor on the proposed/preliminary maps and Base Level

Engineering (BLE) HEC-RAS 2D model to ensure the city’s conveyance systems and detention

ponds are appropriately considered.

Modeling Clarification:

• Work with FEMA to clarify acceptable modeling software and methodologies, given the changes

and mergers in the industry.

5. Recommendations and Reporting

Improvement Proposals:

• Develop a prioritized list of improvements to enhance the city’s drainage infrastructure.

• Provide cost estimates and potential funding sources for each proposed improvement.

Final Report:

• Compile all findings, assessments, and recommendations into a comprehensive final report.

• Present the report to the City of Aberdeen and relevant stakeholders for review and approval.

Conclusion

This comprehensive drainage study is crucial to the floodplain remapping and levee recertification, and it

will provide the City of Aberdeen with critical insights into its drainage infrastructure and flood

management practices. By addressing existing deficiencies and planning for future improvements, the city

can better protect its residents and properties from flooding risks.

The City Manager will appoint a consultant selection committee, which will select the consultants to be

interviewed. Following the interviews, the consultant selection committee will make their

recommendation to the City Council for final selection, at which time City Officials will finalize

negotiations with the highest ranked consultant.

Tasks to be accomplished

1. Meetings with City Staff to determine final scope of the study.

2. Meetings with City Staff to determine all currently available information that may be useful

in preliminary determinations for placement of flow metering, and flow data analysis, etc.

3. Development of plan for identification of problem areas.

4. Installation of appropriate measuring and analytical devices for refining engineering

alternatives for correction of problems.

5. Providing adequate personnel during crucial points of the study.

6. Study alternatives for correction of problems

7. Presentation of alternatives to City Staff and Elected Officials

8. Presentation of Final Findings

Items that would be available to the consultant:

1. GIS Data on storm sewer sizes, materials and locations

2. Historical flood maps

3. Copies of previous drainage studies

4. CAD files and paper drawings of drainage projects, including conveyance, holding ponds and

lift stations

DESCRIPTION OF SERVICES

The consultant will be required to review existing data and work with staff on a needs assessment to help

determine alternatives. The consultant will need to complete all preliminary and final study of the City’s

system, providing recommendations to Public Works/Engineering Staff on corrections and cost estimates

to implement corrections.

TYPE OF CONTRACT

The contract will be on the basis of actual costs plus a fixed fee for the entire scope of services. A detailed

breakdown of labor categories, salary rates, additives and estimated hours will need to be included in the

proposal.

PROPOSED EVALUATION CRITERIA

The consultant selection committee will evaluate and rank each proposal based on the following equally

weighted criteria:

1. Qualifications of the consulting firm – based on previously completed projects of similar

nature to the project contained in this RFP.

2. Qualifications of the consultant’s staff – based on previously completed projects of similar

nature to the project contained in this RFP.

3. Availability of staff to complete the projects within the specified time frames

PROPOSED SCHEDULE

Consultant Proposals Due:

Interview Process Complete

Consultant Selection:

Project Concept & Scoping Meeting

Completion of GIS Data Assessment

Completion of Field Survey

Completion of Model Development and Simulation

Completion of Infrastructure Assessment

Completion of Coordination with Federal Agencies

Presentation of Recommendations and Final Report

March 20, 2026

April 10,2026

April 17, 2026

May 8, 2026

June 26, 2026

September 25, 2026

January 8, 2027

March 5, 2027

May 14, 2027

June 21, 2027

This is the opportunity summary page. It provides an overview of this opportunity and a preview of the attached documentation.

Bid Title:	Requests for Proposals-Consulting Services: Interior Drainage Study
Category:	City of Aberdeen Bid Postings
Status:	Open