HomeMy Public PortalAboutAdd#7 - Bright St Drainage.pdfADDENDUM #07
ADDENDUM # #07 DATE April 30, 2018
ADDENDUM TO CONTRACT City of Tybee Island - City Engineer
DATE OF CONTRACT February 28, 2018.
PROJECT: CITY OF TYBEE ISLAND
BRIGHT ST. DRAINAGE IMPROVEMENTS
THE CITY OF TYBEE ISLAND (Owner) and THOMAS & HUTTON ENGINEERING CO.
(Consultant/Engineer) this 30TH day of April 2018, amend their contract dated February 28th, 2018
for work, materials, or services described below.
I. SCOPE OF WORK:
A. Survey Phase
1. Topographic Survey Phase
Thomas & Hutton Engineering Co. will perform a topographic survey along Logan
Street, Bryan Avenue, Bright Street, Campbell Avenue, Solomon Avenue and Van
Horne Avenue to assist in the design of drainage improvements. The approximate
length of the survey corridor is 3,500 linear feet. Survey corridor width will be the
road right of way width plus ten feet on either side of right of way. The survey will
include the location of ditches, drainage structures, pipes and drainage outfalls.
Road cross-sections will be taken at 100' intervals and at high and low points.
Cross-sections will also be taken through the median between Solomon Avenue
and Van Horne Avenue. Along the south side of Logan Street, building faces will
be located and finished floor elevation and existing ground elevation at the
structures will be obtained. Right of way lines will be re-established for the existing
roads in the survey project area. Property line data for adjoining and adjacent
parcels will be shown based upon Chatham County Tax Assessor information.
Underground utilities will be shown based upon the location of surface
appurtenances. Subsurface utility designation is not included in this scope of
work. Horizontal datum and vertical datum for the survey will Georgia State Plane
Grid, East Zone NAD83 and NAVD88, respectively. Deliverable will consist of an
AutoCAD CiviI3D file.
Survey Phase
Lump Sum $15,300.00
B. General Study/Report Phases
The Consultant shall create an ICPR 4, 1 -Dimensional model to simulate
stormwater flow through the existing stormwater system. The hydrologic and
hydraulic model will include primary existing stormwater conveyances within the
project area simulated to the 25 -year, 24-hour design storm. Drainage basins will
be delineated and mapped. Time of concentration and curve calculations will
City of Tybee Island
Addendum #07
April 30, 2018
Page 2
be in accordance with USDA Technical Release 55 guidance. After model
simulations, the water surface elevations will be reviewed in relation to drainage
structure frame elevations for areas of flooding known as stormwater system
deficiencies. Consultant will review areas of inundation and potential system
improvements. A post -development model will be developed and the planned
improvements will be modeled to alleviate flooding issues within the drainage
area. The Consultant will used Mean High High Water as the tailwater for the
model.
Deliverables for this phase will include:
• ICPR 4, 1 -dimensional model simulating existing stormwater conveyance
for the 25 -year, 24-hour design storm.
General Study/Reports Phase
C. Site Design
Lump Sum $8,500.00
Consultant shall prepare drainage improvement plans. These plans shall be
submitted to the Owner for review. The site development plans will include:
Grading - finish ground elevations, finish contours, and grading
information.
• Drainage - structure location, pipe route and size, inverts and slopes, and
lagoon elevations, including preparation of design calculation.
• Water Distribution - no water relocation design is included with this
proposal. Should it be required it will be addressed through an
amendment to the contract.
• Sanitary Sewer - no sewer relocation design is included with this proposal.
Should it be required it will be addressed through an amendment to the
contract.
• Erosion Control - for planned improvements
• Profiles - drainage
• Construction Details -drainage and erosion control.
• Technical specifications for earthwork, drainage systems, and erosion
control.
• Design calculations - storm drainage
Site Design Phase
D. Permitting
Lump Sum $12,500.00
At this time permitting is not included in this proposal. Thomas & Hutton will
prepare the drainage study and construction plans based on the required
improvements. The level of permitting effort will vary depending on the amount
and types of permits required. Once the improvements have been determined
and the necessary permits can be identified, Thomas & Hutton will submit an
addendum for the permitting and bid assistance.
City of Tybee Island
Addendum #07
April 30, 2018
Page 3
E. Meetings
Thomas & Hutton will attend one (1) kickoff meeting, and two (2) project update
meetings. It is assumed that the first meeting will be at the completion of the
drainage study to review the findings and the second will be at or around the
50% completion point of the construction plans.
Site Design Phase Time & Expense $1,500.00
A. Exclusions
Items not included in the scope of services are as follows:
• Permit
• Cost Estimating
• Construction Services
• Determination of Improvements and Associated Costs
• Accessibility construction compliance verification
• Archaeological survey and report
• Wetland, Coastal Marshland delineation, surveys, or permits
• Geotechnical investigation or report
• Phase One or Phase Two Environmental Assessments
• Endangered species survey and report
• Off-site work unless specifically covered in the scope of services
• Approvals or permits other than those related to the scope of work
covered by this contract
• Act as an expert witness for legal activities
• Georgia Department of Transportation permits or approvals.
• Telephones, cable television, gas, and power distribution systems
These items can be coordinated or provided, if requested by the Owner in
writing.
2. PERIODS OF SERVICE
After receipt of a written notice to proceed from the Owner, Consultant will commence
and complete work upon a mutually agreed upon schedule between Owner and
Consultant.
The above fee arrangements are on the basis of prompt payment of our invoices and
the orderly and continuous progress of the Project.
Project related costs for all printing, travel, reproductions, and materials will be billed as
reimbursable expenses.
City of Tybee Island
Addendum #07
April 30, 2018
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When approved by both parties this Addendum becomes a legal document and a part
of and subject to Terms and Conditions of said Contract.
APPROVED:
APPROVED:
THOMAS & HUTTON ENGINEERING CO. CITY OF TYBEE ISLAN
Title:
Date:
o n V. Giordano, P.E.
Project Manager
`�/3e//0
Title: City Manager
Date: Y/3,07