8-Preliminary Design Concept Report.pdf

PRELIMINARY-FINAL

OCTOBER 24th, 2025

Pre-Final Design Concept Report 40th Street Design from Avenue 6E to Fortuna Road City of Yuma and Yuma County Core Engineering Group, PLLC

City Proj. No.: 0187-ROAD4 Core Job No.: 22-126 October 24th, 2025 Page 1

TABLE OF CONTENTS

I. Executive Summary II. Introduction

a. Forward

b. Description of Project Area

c. Need for the Project

d. Project Objectives

III. Roadway Design

a. Typical Section

b. Horizontal Alignment

c. Vertical Alignment

IV. Corridor Traffic Study V. Drainage Design

a. Topographic Watershed Description

b. Roadway Stormwater Runoff Storage

VI. Environmental Study

a. Unique Farmland

b. Public Involvement

c. Section 4(f)

d. Socioeconomics and Environmental Justice

e. Biological Resources

f. Hazardous Materials

g. Cultural Resources

h. Air Quality and Noise

i. Visual

j. Water Resources

k. Environmental Document

VII. Bridge Analysis

a. Structure Alternatives

b. Recommendation

VIII. Utilities IX. Engineer’s Opinion of Probable Construction Costs X. Conclusion and Recommendations

a. Phasing

b. Recommendations

APPENDICES

Appendix A: 15% 40th Street Corridor Concept A and B Plans Appendix B: Traffic Study by Southwest Traffic Engineers (attached separately) Appendix C: Environmental Considerations Memorandum by Logan Simpson Design (attached separately) Appendix D: Initial Bridge Selection Memo by WSP (attached separately) Appendix E: Engineer’s Opinion of Probable Construction Costs

I. Executive Summary

The Design Concept Report for 40th Street from Avenue 6E to Fortuna Road evaluates options to accommodate the existing and growing traffic in the Yuma Mesa area. The traffic south of Interstate 8 is currently constrained in the east-west direction with only one all-weather access corridor along 32nd Street / South Frontage Road. The City of Yuma and Yuma County collaborated to analyze and develop a cohesive approach to the development of the 40th Street corridor. As 40th Street is only one mile south of the 32nd Street / South Frontage Road corridor and is in the midst of the growing portion of the Yuma Mesa, it will provide relief for the local traffic and more direct routing for public safety and emergency response services.

There are three options in the DCR. Option 1 – “Do nothing” option. This would maintain the status quo and let the continual degradation of traffic operations along the existing corridors. Future private development would need to address their own concerns in a non-coordinated manner. This will cause disjointed development and likely not provide for any provision to cross the SR195 corridor.

Option 2 addresses immediate needs at lower costs in Concept A. Concept A includes a two-lane roadway section, connecting existing sporadic segments of two-lane paved roadway sections. Within Concept A there are two sub-concepts A1 and A2. The 1 designation is a grade-separated crossing with no ramp connections. This reflects the existing access-control condition of SR-195. The 2 designation recognizes recent conversations with the Arizona Department of Transportation relating to the potential for a temporary access control change to allow an at-grade intersection with SR-195 and 40th Street. This would eliminate the need for a bridge structure, retaining walls and the relocations of the City of Yuma 30-inch water transmission main and 36-inch sewer main in the interim. Ultimately, when the 40th Street traffic flows begins to significantly impact SR-195 traffic flow, a grade separation will be required.

Option 3 addresses the full buildout of the 40th Street corridor to the master roadway plans. This option also consists of two sub-concepts, Concepts B1 and B2. The 1 and 2 designations are the same as the Option 2 sub-concepts with 1 designation is a grade-separated crossing of SR-195 and the 2 designation allows for the temporary at-grade intersection with SR-195 and 40th Street.

In order to achieve the goal of providing additional traffic flow options for the growing of Yuma Mesa, the recommended option is Option 2. Within Option 2, the Concept A2 is the most feasible without the cost of the bridge structure. The Engineer’s Opinion of Probably Construction Costs of Concept 2A is $27,716,613 with phasing of implementation in the corridor as funding become available.

City of Yuma and Yuma County Core Engineering Group, PLLC

City Proj. No.: 0187-ROAD4 Core Job No.: 22-126 October 24th, 2025 Page 2

II. INTRODUCTION

a. Forward

This Pre-final Design Concept Report (DCR) is prepared in accordance with a professional services contract between the City of Yuma and Core Engineering Group, PLLC (Core). Yuma County has a separate agreement with Core for the eastern portion of the corridor that remains unincorporated. The purpose of this DCR is to document the improvements needed to increase the east-west connectivity on the Yuma Mesa and develop a phasing and improvement plan for the 40th Street corridor. The improvements will include the interim improvements to provide full connection of at least one lane in each direction and the ultimate improvements to match the Roadways Master Plan of two lanes in each direction and full developed intersections. In each phase, considerations are given for future and current developments along the corridor.

b. Description of Project Area

40th Street from Avenue 6E to Fortuna Road is classified as a Minor Arterial Roadway (City of Yuma Transportation Master Plam, October 2014) and connects the center of the Yuma Mesa area with the Yuma Foothills area. The roadway is currently partially constructed as development has occurred along the corridor. The corridor is currently physically blocked by the SR-195 Area Service Highway. SR-195 is a state limited access facility and currently does not have access provided at the 40th Street alignment. The majority of the development is zoned or will be zoned Residential with some minor Commercial at the Fortuna Road intersection.

c. Need for Project

The City of Yuma’s primary growth area is the Yuma Mesa. This preserves the high-producing agricultural areas in the Yuma Valley and protects the mission of the Marine Corps Air Station Yuma. The roadway options for travel of local traffic as well as regional traffic are limited in the east-west direction. Interstate 8 (I-8) provides east-west freeway-speed connection with access points only at the Araby Road (SR195), Avenue 81/2 E and Fortuna Road interchanges. Besides I-8 itself, only North Frontage Road/32nd Street serves south of the interstate with an all-weather travel service for east-west traffic. The eastern portion of the North Frontage Road is only one lane in each direction with average traffic volumes of 17,097 vehicles per day (vpd). 32nd Street portion of the corridor has two-lanes in each direction with volumes of 26,323 vpd per the Yuma Metropolitan Planning Organization’s Quarterly Traffic Count Program for the year 2024.

To support growth on the Yuma Mesa, this project provides the correct planning for the east-west corridor. The prevention of the existing roadways continuing to degrade and support the emergency vehicle response times as well as general community connection are the primary needs for this project.

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page 3

d. Project Objectives

The objective of this DCR is to analyze three options for the project corridor. Option 1 is the “Do Nothing” Option.

This option allows for the growth of the Yuma Mesa to continue as it is without a coordinated plan of 40th Street development. The construction will be primarily performed by developers as the Yuma Mesa builds out any guiding document or defined plan to follow between sections. This will also lead to the delay of the 40th Street crossing of SR-195 or no construction of the crossing.

Option 2 is the development of Concept A. Concept A is the interim phased development of the 40th Street corridor.

This will connect the existing sections of roadway by constructing 2 lanes of paved roadway with median and a multiuse path. The planning of Concept A accommodates the future full four-lane corridor connection, including the crossing of the SR-195 corridor.

Option 3 is the development of Concept B, which is the ultimate buildout of the entire corridor to two-lanes in each direction and fully developed intersections including left and right turn lanes as required. It will also include a multiuse path, curb, gutter, sidewalks, and stormwater infrastructure. The Concept B preliminary plans and the Engineer’s Option of Probable Construction Costs show the full construction of the four-lanes. It does not account for the development of Concept A first and then the future construction of Concept B.

Both phases have sub-concepts concerning the crossing of the SR-195 corridor. The first sub-concept (Concept A1 or B1) includes an alternative for a grade separation of SR-195 with no connection to the SR-195 roadway. This maintains access control as the State has currently defined it. The second sub-concept (Concept A2 or B2) is an alternative to construct an at-grade intersection with SR-195. This option will require a modification to the State access control. Discussions with Yuma ADOT Southwest District show support for this alternative in an interim condition until such time as SR-195 traffic demands rise to needing the intersection to be removed and the grade separation constructed.

III. ROADWAY DESIGN

The intention of the roadway design is to implement the current City of Yuma Construction Standard Detail Drawings (May 2019) with modifications to reflect the unique needs, characteristics and phasing for the 40th Street Corridor.

a. Typical Section

The typical section for Concept B corridor development is based upon the City Standard 02-015 Minor Arterial Street.

The Concept A typical section will be developed from the Concept B section in order to allow for expansion of the Concept A typical section into the Concept B Section.

Modifications of the Concept B section include widening the raised median to 18-feet in width and development of a ten-foot multi-use path in place on the sidewalk on the north side of the roadway.

The Concept A typical section shall construct the 18-foot median and the adjacent lane in each direction with a 6-foot ABC shoulder. The ten-foot multiuse path will also be constructed.

These typical sections shall be modified in order to accommodate right turn lanes, left turn lanes and double left turn lanes as determined by the traffic study. The sections may additionally be modified to connect with previously constructed roadway sections as is feasible. The modifications shall maintain the overall operation of the various phases of improvements while may not exactly meet the dimensional characteristics.

The previously constructed roadway sections have been constructed throughout the corridor as needed by development. These sections are generally two-lane roadways, some with curb and gutter.

EXISTING 40TH STREET ROADWAY SECTIONS

Beginning End No. of Lanes Ex. Median Ex. Curb and Gutter

Avenue 7 1/2E Avenue 8E 2 Yes – Full No

Avenue 8 1/2E Cactus Wren Way 2 Yes – South Half

Yes – South C and G

Cactus Wren Way Avenue 9E 2 No No

Avenue 10E Fortuna Road 2 No Yes – North C and G

Additionally, to these existing sections, the City of Yuma anticipates construction of the Avenue 7E intersection from Avenue 6 3/4E to Avenue 7 1/2E with one lane in each direction and a raised median. The design shall reflect these improvements as existing improvements.

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page 4

b. Horizontal Alignment

The horizontal alignment of the 40th Street corridor is primarily based upon the section line alignments within the corridor. The existing right-of-way designations are based upon these section lines. The horizontal alignment will be altered from the section line as needed in order to minimize takings of homes and developed property in right-of-way acquisition. The modifications are documented in the 15% plans in Appendix A. The horizontal alignment will not vary between Concept A and Concept B even if the improvements are not centered on the horizontal alignment, particularly in Concept A.

The side streets will be provided in the roadway development. Not all side streets will be provided with full access.

Most side streets are not at mid-section and section lines shall not accommodate left turns. The median will dictate the right-in-right-out scenario for access control.

c. Vertical Alignment

The vertical alignment for the 40th Street corridor is primarily based upon efficient stormwater runoff design and effective earthwork balance. Given the excessive blowing of sand as the Yuma Mesa remains undeveloped, the profile of the roadway may need to remain slightly elevated to help with maintenance activities. The minimum longitudinal slope is 0.3% to provide positive drainage and allow for tolerances to the City Standard minimum slope of 0.2%.

The vertical alignment is established with the ultimate construction of Concept B. The resulting earthwork in Concept A may not be ultimate in interim conditions, but ultimate buildout design shall govern. The side streets may need partial reconstruction to ensure transition to the vertical alignment.

The sub-concept of the grade separation over SR-195 will have the most extreme longitudinal grades throughout the whole project. Ideally, maximum slopes of less than 5% meets American with Disabilities Act criteria, however the Act does not require roadways to conform with the 5% maximum.

IV. CORRIDOR TRAFFIC STUDY

As part of the DCR process, Southwest Traffic Engineers is performing a corridor-wide traffic analysis to determine project volumes and characteristics of 40th Street. This effort includes the following tasks:

a. Field observation of the surrounding area was conducted to evaluate the existing physical and operational characteristics of the adjacent roadway network.

b. Traffic volumes generated by development zones within the study area will be calculated using the Institute of Transportation Engineers (ITE) Trip Generation Manual, 11th Edition, 2021.

c. Trip generation for the development zones within the study area will be distributed to 40th Street based on accessibility to the roadway and historic traffic volumes.

d. Yuma Metropolitan Planning Organization (YMPO) transportation models will be examined for future traffic projections along 40th Street.

e. Roadway cross section and intersection geometric requirements will be determined based on Maricopa County Department of Transportation (MCDOT) guidelines. The need for auxiliary turn lanes at the study intersections were evaluated based on Arizona Department of Transportation (ADOT) guidelines.

f. Traffic Signal Warrants will be evaluated at the following intersections based on existing and 2045 traffic volumes without and with the development zones.

INTERSECTIONS FOR SIGNAL WARRANT

STUDIES

Intersection Existing Intersection

Jurisdiction

Avenue 6 E Yes City of Yuma

Avenue 7 E No City of Yuma

Avenue 7½ E Yes City of Yuma

Avenue 8 E Yes City of Yuma

Avenue 8½ E No City of Yuma

Avenue 9 E No City of Yuma

Mesa Avenue No City of Yuma

Avenue 10 E Yes City of Yuma

Fortuna Road Yes (Ex. Signal) Yuma County

For the purpose of this DCR, it is assumed that no new traffic signals will be required along 40th Street and that all intersections will be stop-controlled for Concept A; all traffic signals are anticipated during the construction of Concept B. The only exception to this assumption is the traffic signal in Concept A2. It is assumed that the traffic signal at the at-grade intersection with SR-195 will require a signal.

V. DRAINAGE DESIGN

a. Topographic Watershed Description

The watershed is comprised of Rosita Sand and Rosita – Ligurta Complex soil types. The porosity of the native soil prevents accumulation of runoff in a concentrated flow to create washes. The average annual rainfall for this water shed is 2.25 inches per hour in the 10-year design horizon. The average percolation rate of native soil is conservatively 6 inches per hour (per Soil Survey of Yuma-Wellton Area, by US Department of Agriculture).

City of Yuma and Yuma County Core Engineering Group, PLLC

City Proj. No.: 0187-ROAD4 Core Job No.: 22-126 October 24th, 2025 Page 5

b. Roadway Stormwater Runoff Storage

There are no regional retention basins planned or existing in the project area. The adjacent residential subdivisions collect and retain the runoff generated within the subdivisions. Any future commercial development along the corridor will also be required to store runoff on-site per building codes for the City of Yuma and Yuma County. Typical subdivision development criteria require the storage of runoff from the adjacent arterial roadways.

i. Concept A

Concept A does not have curb and gutter; therefore, runoff will be collected in the shoulder area of the roadway. Storm drain pipes will be installed underneath paved areas to accommodate the ultimate buildout for Concept B.

ii. Concept B

The roadway runoff will be collected in retention basins at or near the low point of the profile of the 40th Street roadway in the ultimate buildout of Concept B. Small, discrete storm drain systems will collect the runoff and route to the local retention basins. Existing subdivisions that have accommodated this runoff volume will be utilized to the greatest extent possible. The new retention basins for the roadway runoff may be relocated to the future subdivision retention basin and the right-of-way for the retention basin may be abandoned.

By City and County codes, standing water must be evacuated from the basin within 72 hours. Given the native soil percolation rate and the anticipated retention basin depth of three and one-half feet, the basins will percolate into the soil within 7 to 12 hours, thereby exceeding the code criteria.

VI. ENVIRONMENTAL STUDY

The Environmental Considerations Memorandum (ECM) was produced by Logan Simpson Design (LSD) as part of the DCR process for 40th Street Corridor. The project will need to comply with the National Environmental Policy Act (NEPA) to be eligible for Federal funding. The ECM investigated the following areas ahead of the completion of the final environmental documentation.

a. Unique Farmland

The project area is 70% undeveloped and classified as Unique Farmland, however not currently under cultivation. The Farmland Protection Policy Act (FPPA) does not apply to the project lands due to the lack of active farming.

b. Public Involvement

As the remainder of the environmental process is completed, there will be a public meeting required and notice to agencies to meet the NEPA requirements.

c. Section 4(f)

The project is not anticipated to impact any Section 4(f) properties as defined in the Department of Transportation Act of 1966.

d. Socioeconomics and Environmental Justice

The project is not anticipated to cause any residential displacements or disproportionately impact minority, low-income or limited English-speaking populations.

e. Biological Resources

The project is not anticipated to impact any federally listed species from the Endangered Species Act (ESA). Although not in the ESA, the Flat-Tailed Horned Lizard (FTHL) is protected under a multi-agency conservation agreement. The project area is not within the management area of the plan, however federal agencies may recommend implementation of portions of the 2003 FTHL Rangewide Management Strategy. LSD will conduct a biological survey to verify these assumptions.

f. Hazardous Materials

According to the regulations in the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), the preliminary review indicates no known hazardous waste sites within or adjacent to the project site. LSD will perform a preliminary initial site assessment to meet ADOT requirements.

g. Cultural Resources

According to the National Historical Preservation Act (NHPA) and the Arizona Antiquities Act, the initial results from the Class III Pedestrian Cultural Resources Survey identify 2 canals within the project limits potentially meeting the relevant criteria. The NHPA Section 1006 consultation process will proceed for any potential impacts to the structures.

h. Air Quality and Noise

The EPA designation of the Yuma area as a PM10 non-attainment area requires a qualitative air quality assessment to receive federal funds for the project construction. Additionally, a qualitative noise study will be performed to meet 2017 ADOT Noise Abatement Requirements.

i. Visual

No visual resource analysis is anticipated to be required.

j. Water Resources

The project area contains the two canals, it is not anticipated that either canal will be determined to be Jurisdictional Waters of the United States. The project construction activities will require a Notice of Intent (NOI) and a Storm Water Pollution Prevention Plan (SWPPP) per the Arizona Pollutant Discharge Elimination System (AZPDES). This will be prepared during final design and submitted by the future contractor prior to construction activities commencing.

k. Environmental Document

Recently, the requirement of which specific required environmental document appropriate is in the process for review. LSD will perform the document as directed pending clarification.

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page 6

VII. BRIDGE ANALYSIS

The grade-separate crossing proposed under Concepts A1 and B1 are analyzed by WSP as part of this DCR in the Initial Bridge Selection Memo (IBSM). It is assumed that the full bridge structure will be constructed under Concept A1, should that be the chosen Option. The ability to construct the bridge structure in phases is possible, however likely to cost more due to future shoring and construction activities.

a. Structure Alternatives

The IBSM investigates three options for the bridge structure for the 40th Street overpass of SR-195. The bridge types include:

i. ALTERNATIVE 1: PRECAST PRESTRESSED UBT50 CONCRETE GIRDER BRIDGE

ii. ALTERNATIVE 2: STEEL PLATE GIRDER BRIDGE

iii. ALTERNATIVE 3: PRECAST PRESTRESSED AASHTO BIV-48 ADJACENT BOX

GIRDER BRIDGE

It is assumed that the foundation type for all alternatives is 72-inch diameter drilled shafts given the successful historical construction techniques in the Mesa Sand. Driven piles may also be an option;

however, a geotechnical investigation is necessary before the option can be evaluated. This is anticipated to be completed in final design.

The drilled shafts shall have 48-inch (Alt Nos. 1 and 2) or 54-inch (Alt. No. 3) circular concrete columns that may be modified for bladed, rectangular or other shapes as City desires.

b. Recommendation

The following is the summary of the alternatives from the IBSM with the recommendation to implement Alternative 1. It is important to note that along with the bridge construction costs, the relocation of the 30” water transmission main and the 36” sewer interceptor will be a necessary cost on top of the structures cost.

VIII. UTILITIES

The 40th Street corridor is and will continue to be a utility corridor to serve the Yuma Mesa as well as the development in the area. The following list of utilities are within the corridor. The conflicts with design will be identified early and addressed directly with each agency. Utility Clear Letters will be obtained from each utility company prior to the completion of final design.

The greatest impact to existing utilities is the conflict between the construction of the SR-195 bridge and the two major City of Yuma utilities. The 40th Street corridor contains a 30-inch water transmission main and a 36-inch sewer interceptor, both which serve the Yuma Mesa. Their locations are central to the 40th Street right-of-way, causing direct conflict with bridge construction. It is assumed for both Concept A1 and Concept B1 that both lines will require about a six hundred foot relocation and jack and bore underneath SR-195 to accommodate the foundation system.

40th STREET UTILITIES

Company Utility

Allo Communications CATV, Fiber Optic, Telco

Arizona Department of Transportation Storm Drain, Culverts, Lighting Traffic Signals

Arizona Public Service Electric

Bureau of Reclamation / Yuma Mesa Drainage and Irrigation District Irrigation

Charter Communications Coaxial, Fiber Optic

City of Yuma Sewer, Water, Storm Drain, Lighting

Crown Castle Solutions Corporation Fiber Optic

CenturyLink Communications Coaxial, Fiber Optic

City of Yuma and Yuma County Core Engineering Group, PLLC

City Proj. No.: 0187-ROAD4 Core Job No.: 22-126 October 24th, 2025 Page 7

El Paso Natural Gas Natural Gas

Foothills Utilities Sewer, Water

Lumen Fiber Optic

MCI – Verizon Business Fiber Optic

Southwest Gas Corporation Gas, High Pressure Gas

Western Area Power Administration Electric

IX. ENGINEER’S OPINION OF PROBABLE CONSTRUCTION COSTS

The tables in Appendix E detail the Engineer’s Opinion of Probable Construction Costs (EOPCC) for the four implementation scenarios (sub-concepts). The appendix contains the detail of the development of the EOPCC for Concept A1, Concept A2, Concept B1 and Concept B2. The details assume the development of the whole corridor under the specific concept scenario. There is no consideration of the development of Concept A1 in the EOPCC for Concept B1, nor consideration in Concept B2’s EOPCC for any construction of Concept A2. Given the duration of time until construction and the lack of final design-level plan development, a contingency of 45% is utilized in each

EOPCC.

X. CONCLUSION AND RECOMMENDATIONS

The development of the 40th Street corridor to serve the recent and future growth of the Yuma area is greatly needed.

The ability to travel to the east and west, south of I-8 is limited to the 32nd Street/South Frontage Road corridor. This can become problematic in servicing the area with emergency response and creates congested locations in the southern portion of the Yuma Mesa. The 40th Street corridor will be that secondary route that traverses SR-195.

a. Phasing

The development of the 40th Street corridor in the entirety of either Concept A or Concept B is not likely.

The City and the County shall have the ability to construct the selected concept in phasing intervals as needed and as funded. There are many scenarios of phasing that seem likely. For instance, the construction of the segment of roadway from Avenue 6E to Avenue 7E could ideally be implemented early to provide an additional crossing of SR-195 and help relief congestion on the 32nd Street and SR-195 intersection. These phases shall be made at the determination of the jurisdiction and final design efforts will address temporary connection issues as relevant.

b. Recommendations

The conclusions of this DCR are based upon the cost effectiveness of implementing the connectivity needed for the growing area of Yuma. Implementing the lowest-cost alternative that provides the much-needed relief to the east-west traffic patterns of the Yuma Mesa is the best option. Therefore, Option 2 provides that connection. Given the cost differential between the sub-concepts, implementing the two-lane concept with the at-grade intersection with SR-195, Concept A2, provides the greatest relief at the lowest cost. Additionally, the current willingness of ADOT to allow access to SR-195 at the 40th Street alignment will additionally create more options for traffic flow on the Yuma Mesa and throughout the County. Further, the grade-separated concepts provide reduced access opportunities and much higher probable construction costs due to the bridge structure, retaining walls, water transmission line relocation and the sewer interceptor relocation, making these options undesirable.

The likely improvements will be completed in phases, first with segments from Concept A2 and eventually widening to include the build-out to Concept B2 improvements. This progression will likely be driven by regional development as the community continues to grow. Finally, a future need will require a grade-separated scenario to accommodate the SR-195 higher traffic volumes.

ENGINEER’S OPINION OF PROBABLE

CONSTRUCTION COSTS

Option Sub-Concept EOPCC Estimate

1 No Build $0

A1 (2-lane grade-separated) $45,078,443

A2 (2-lane at-grade) $27,535,512

B1 (4-lane grade-separated) $73,121,551

B2 (4-lane at-grade) $56,312,976

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page A

APPENDIX A:

Pre-Final 40th STREET CORRIDOR CONCEPTS A AND B PLANS

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page B

APPENDIX B:

TRAFFIC STUDY

BY SOUTHWEST TRAFFIC ENGINEERS

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page C

APPENDIX C:

ENVIRONMENTAL CONSIDERATIONS MEMORANDUM

BY LOGAN SIMPSON DESIGN

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page D

APPENDIX D:

INITIAL BRIDGE SELECTION MEMO

BY WSP

City of Yuma and Yuma County Core Engineering Group, PLLC

Core Job No.: 22-126 October 24th, 2025 Page E

APPENDIX E:

ENGINEER’S OPINION OF PROBABLE CONSTRUCTION COSTS

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Core Job No.: 22-126 October 24th, 2025 Page F

City of Yuma and Yuma County Core Engineering Group, PLLC

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