CN-370000-BS135-T18.pdf

Tracy Woods Digitally signed by Tracy Woods Date: 2023.10.24 10:35:52 -04'00'

Deneka Smith Digitally signed by Deneka Smith Date: 2023.10.26 14:09:52 -04'00'

Keisha Akhavein Digitally signed by Keisha Akhavein Date: 2023.10.26 16:04:07 -04'00'

Digitally signed by John A. Coates Date: 2023.10.26 23:01:22 -04'00'

Compilation of Existing Available Data and the Filling in of Data Gaps including Surveying Lake Bathymetry and Hydrologic Modeling inputs for One (1) High Hazard Potential Dam System, in Polk County and One (1)

High Hazard Potential Dam System, in Hillsborough County, Owned by the Southwest Florida Water Management District, FL

SCOPE OF SERVICES 10/13/2023

Background and Project Description:

Mott MacDonald is pleased to submit this proposal to the Florida Department of Environmental Protection (FDEP) to conduct required professional engineering services for Task Assignment Number 18 under FDEP Contract No. BS135. The engineering services involves the compilation of existing data available and filling in data gaps including surveying lake bathymetry and hydrologic modeling input for two (2) High Hazard Potential (HHP) Dam systems owned by the Southwest Florida Water Management District (SWFWMD). One HHP system, which includes control structures P1 and P3, is in Polk County and the other HHP system, which includes the Flint Creek control structure at Lake Thonotosassa, is in Hillsborough County.

PROJECT INFORMATION

The requested services include:

1. On-site Field Reconnaissance and attendance at an initial meeting with FDEP,SWFWMD and local County representatives to:

a. Arrange for the collection of existing electronic data files where available.

b. Collect available pertinent hard copy/ data files of the control structures.

c. Discuss pertinent issues of concern and confirm the availability and transfer of available watershed data identified in Data Documentation and Gap Analysis Report in Task Assignment Number 16.

2. Conducting Field surveying of the control structures at the lakes associated with P3 and P1 and Flint Creek.

3. Conducting Hydrographic - Bathymetry Data Acquisition and Data Review at Lake Whistler Lake Ariana and Lake Lena in Polk County; and at Lake Thonotosassa in Hillsborough County.

4. Developing Hydrologic Modeling Inputs for the watershed subareas within project domain areas for future inundation modeling and mapping required to support the development of Emergency Action Plans for the two HHP system dam systems.

SCOPE OF SERVICES

Task 1: Field Reconnaissance Site Visit and Coordination with FDEP, SWFWMD and Local County representatives.

The following work tasks will be performed to document the available pertinent data for the below listed two (2) HHP dam systems in Polk County and Hillsborough County, FL.

1. P-1 Lake Lena Structure, National Inventory of Dams (NID) ID # 13345, Polk County and

P-3 Lake Arietta Structure NID # 12011, Polk County

2. Flint Creek Structure NID ID # 12037, Hillsborough County

A. Conduct on site field reconnaissance and attend an initial meeting, with the representatives of the Department, SWFWMD, Mott MacDonald, and local county representatives to discuss pertinent project issues of concern and arrange to collect the available data items regarding the control structures at the impoundments, as follows:

1) P-1 and P-3 Control Structures and Lake interconnect structures.

• As-built drawings - plan, elevation, details, and cross-sections

• Latest Inspection Reports

• Project Hydrologic design criteria/ data

2) Watershed / sub watersheds Planning Reports

• Watershed planning reports - electronic files.

• Lidar and topographic data - electronic files

• Hydrologic Modeling data - electronic files

3) Existing Field Survey and Bathymetry data

• Existing field survey data of the impoundments - electronic files

• Existing bathymetry survey data of the impoundments - electronic files Existing Operations Plans for the Control Structures

• Operations plan / manual for structures - electronic files

B. Compilation of retrievable available data identified above and in the Data Documentation and Gap

Analysis Report in Task Assignment Number 17.

DELIVERABLES:

1) Prepare and submit electronic files for Draft and Final Site Reconnaissance Summary Reports, after review by FDEP, including:

• Appendices with Figures and Excel Tables - summarizing data findings, Photos and recommendations regarding Points of Interest (POI) locations and downstream consequence areas during extreme storm events.

2) Electronically submit Existing Data Available Table for the P1 – P3 Control Structures and Lake Thonotosassa /Flint Creek systems, including inspection reports, as built documents and bathymetry data provided by SWFWMD.

Performance Measure: Deliverables will be reviewed by the Department to confirm that they are complete, accurate, and timely.

Task 2: Field Survey & Hydrographic - Bathymetry Data Acquisition and Data Review

Refer to Figures 1 through 6 for Polk County project area. Conduct field surveying and hydrographic -bathymetry data acquisition at Structure P-3, Lake Whistler inflow and outflow, Lake Ariana inflow and outflow, Lake Lena Inflow, Structure P-1 outflow, and:

1) Establish the top of embankment profiles and cross sections at the control structures and collect lake inlet and outlet works dimensions data necessary to support future hydrologic analyses.

2) Confirm (ground truth) site topographic mapping at the Lakes embankment at the control structures.

3) Conduct hydrographic -bathymetric survey of the Lake Whistler impoundment to establish the elevation -storage - area relationships between the bottom of the lake, operating pool level and top of dam. Retrieve existing available Bathymetry data for Lake Ariana and Lake Lena and establish the elevation -storage - area relationships between the bottom of the lakes, operating pool levels and top of dam embankments.

Refer to Figures 7 through 9 for Hillsborough County project area. Conduct field surveying and hydrographic - bathymetry data acquisition; and field verification at Lake Thonotosassa and at Flint Creek Structure outflow works, and:

1) Establish the top of embankment profiles and cross sections at the control structures and collect lake inlet and outlet works dimensions data necessary to support hydrologic and hydraulic analyses.

2) Confirm (ground truth) site topographic mapping of the Lakes embankment at the control structures.

3) Conduct limited hydrographic -bathymetric survey verification at Lake Thonotosassa impoundment. This data in conjunction with existing available lake bathymetry data shall be used to establish the elevation -storage - area relationships between the bottom of the lake, operating pool level and top of dam embankment. Refer to Figure 13.

1) Provide e-mail notification to the FDSP at least one week prior to any scheduled site visit and

/ or to meet with the owner or their representative, and to conduct the required field surveying and hydrographic-bathymetry survey work. The notification should include the date, time, meeting location, and the vendor contact name and phone numbers (office and cell). The e-mail notification should be sent to Tracy.Woods@FloridaFDEP.gov

2) Provide an electronic version of the original field surveying data obtained for the dam structures and survey report, along with photographs taken at the selected field survey locations.

3) Provide an electronic version of the hydrographic-bathymetry data gathered, as a Bathymetry Digital Elevation Model (BEM) along with corresponding Geographic Information System (GIS) shape files for the impoundment areas.

Task 3: LiDAR Data Compilation and Analysis and Bathymetry data merging

Conduct LiDAR Data collection and Analysis for the two HHP dam impoundment systems study area, Refer to Figure 11.

1) Collect existing available 2018 SWFWMD LiDAR DEM and GIS data set for the P-1 and P-3 Polk County Impoundment system domain area; and available 2017 LiDAR DEM for the Lake Thonotosassa Flint Creek Outflow structure and downstream project area for Hillsborough mailto:Tracy.Woods@FloridaFDEP.gov

County from the https://rockyweb.usgs.gov website data delivery system and tailor coverage areas as needed for project works.

2) Download the available respective 2017and 2018 LiDAR data and pertinent data sets and produce a DEM for the two HHP dam systems, in Polk and Hillsborough Counties, project study domain areas using GIS methods.

3) Integrate the 2018 LiDAR bare earth Digital Elevation Models(DEMs) with the Bathymetry Digital Elevation Models (BEMs) hydrographic survey data developed in Task 2 to produce a seamless merged DEM/BEM for the Polk County P-1 and P-3 impoundments and their downstream flooding impact areas.

4) Integrate 2017 LiDAR bare earth Digital Elevation Model(DEM) with the Bathymetry Digital Elevation Model (BEM) hydrographic survey data developed in Task 2 to produce a seamless merged DEM/BEM for the Hillsborough County Lake Thonotosassa Flint Creek Outflow structure impoundment and its downstream flooding impact area.

1) Provide a merged DEM/BEM product in electronic format for the Polk County P-1 and P-3 impoundments project study area with GIS shape files. This DEM/BEM product will serve as the pre-requisite for the future hydrologic modeling work activity.

2) Provide a merged DEM/BEM product in electronic format for the Hillsborough County Lake Thonotosassa Flint Creek Outflow structure impoundment project study area with GIS shape files. This DEM/BEM product will serve as the pre-requisite for the future hydrologic modeling work activity.

Task 4: Project domain watershed Hydrologic modeling inputs for the Polk County and Hillsborough HHP dam systems

Develop project domain watershed characteristics for both Polk County and Hillsborough County HHP dam systems to include:

1) The delineation of watershed subareas contributing flow to the selected points of interest for the Polk County P-1 and P-3 HHP dam system impoundments and downstream flooding impact area including base watershed map figure(s), and NRCS soils and Hydrologic Soil Group data. Refer to Figures 10 and 11.

2) Establish elevation- area-cumulative storage tables for the Polk County lakes of interest, including elevation, area and cumulative storage volume table for Lake Whistler, Lake Ariana and Lake Lena impoundments in the HHP dam system. Refer to Figure 12.

3) The delineation of watershed subareas contributing flow to the selected points of interest for the Hillsborough County Lake Thonotosassa Flint Creek HHP dam system impoundment and downstream flooding impact area; including base watershed map figure(s),and NRCS soils and Hydrologic Soil Group data. Refer to Figure 7. The Flint Creek project domain extends downstream to the north and west to the confluence with Hillsborough River just downstream of the N.US Highway 301 crossing.

4) Establish elevation- area-cumulative storage tables for the Hillsborough County Hillsborough

County Lake Thonotosassa Flint Creek HHP dam system and elevation, area, and cumulative storage volume table for the Lake Thonotosassa Flint Creek HHP dam system. Refer to Figure 13.

1) Provide watershed subareas map contributing flow to the selected points of interest for the Polk County P-1 and P-3 HHP dam system impoundments and downstream flooding impact area.

2) Provide elevation- area-cumulative storage tables for the Polk County Lake Whistler, Lake Ariana and Lake Lena impoundments.

3) Provide watershed subareas map contributing flow to the selected points of interest for the Hillsborough County Lake Thonotosassa Flint Creek dam system impoundment and downstream flooding impact area.

4) Provide elevation- area-cumulative storage tables for the Lake Thonotosassa Flint Creek dam system impoundment.

Key Personnel

FDEP

Role Name Entity

Project Manager Tracy Woods FDEP

Contract Manager Deneka Smith FDEP

Mott MacDonald

Role Name Entity

Project Principal David Skipper Mott MacDonald

Project Manager James Johnson Mott MacDonald

Principal Engineer Michael Cox Comak Group

Project Schedule: CONSULTANT is available to begin work on this project immediately following receipt of the executed Task Assignment Number 18 from FDEP.

Compensation and Method of Payment

Compensation to be paid to the Consultant for providing the services described herein shall be on a fixed-price basis for each Task Deliverable. No compensation will be paid for services and/ or tasks that are not performed. The fixed-price compensation for the Deliverable shall be as listed in the detailed Payment and Deliverables Schedule Table. See Appendix A for Payment and Deliverables

Schedule Table.

The Consultant will submit invoices to the FDEP for work performed at the completion and acceptance by FDEP of the final deliverable. The invoicing will be accompanied by a brief description of the work effort completed, including deliverables achieved, in accordance with the attached Fee

Schedule. Compensation will not be paid for a deliverable until the deliverable has been completed and accepted by the FDEP.

AUTHORIZATION

The following individual is a representative for the CONSULTANT with the authority to enter into a binding Contract with the FDEP:

Signature Date

11/1/23

Name and Title

David Skipper, PE – Senior Vice President

Company Name

Appendix A

PAYMENT AND DELIVERABLES SCHEDULE

For all tasks, payment shall be made on a fixed price basis in the fixed amounts specified below for each deliverable following receipt and acceptance by the FDSP in accordance with Contract Terms.

Deliverable Deliverable Description Due Date

Total

Payment

Amount

Task 1

Field Reconnaissance Site Visit and Coordination with FDEP, SWFWMD and Local County representatives.

1) Draft & Final Site Reconnaissance Summary Report

2) Existing Data Available Table for the P1 – P3 Control Structures and Lake Thonotosassa impoundments system

12/11/2023

$2,428.64

Task 2

Field Survey & Hydrographic - Bathymetry Data Acquisition and Data Review

1) Provide e-mail Notification of schedule site visit to FDEP

2) Provide electronic file of field surveying data for both Polk

County and Hillsborough County HHP dam systems

01/08/2024

$34,965.28

Task 3

LiDAR Data Compilation and Analysis and Bathymetry data merging

1) Compile DEM from 2018 LiDAR and Hydrographic BEM data developed for the Polk County P-1 and P-3 impoundments.

2) Compile DEM from 2017 LiDAR and Hydrographic BEM data developed for the Hillsborough County Lake Thonotosassa Flint Creek Outflow structure impoundment.

3) Provide a merged DEM/BEM product in electronic format for the Polk County P-1 and P-3 impoundments project study area with GIS shape files.

4) Provide a merged DEM/BEM product in electronic format for the Hillsborough County Lake Thonotosassa Flint Creek Outflow structure impoundment project study area with GIS shape files.

02/16/2024

$5,538.24

Deliverable Deliverable Description Due Date Total

Payment

Amount

Task 4

Project domain watershed Hydrologic modeling inputs for the Polk County and Hillsborough HHP dam systems

1) Provide watershed subareas map contributing flow to the selected points of interest for the Polk County P-1 and P-3 HHP dam system impoundments

2) Provide elevation- area-cumulative storage tables for the Polk County Lake Whistler, Lake Ariana and Lake Lena impoundment

3) Provide watershed subareas map contributing flow to the selected points of interest for the Hillsborough County Lake Thonotosassa Flint Creek dam system impoundment

4) Provide elevation- area-cumulative storage tables for the Lake Thonotosassa Flint Creek dam system impoundment

03/25/2024

$8,076.32

TOTAL $51,008.48

Appendix B

Project Figures

(Figures 1 through 13 pdfs included as a Separate Attachment)

Appendix C

SSMC Topographic & Bathymetric Survey Proposal

(Included as a Separate Attachment)