HomeMy WebLinkAboutTIC 2018-09-10 Item 2D - Contract Amendment #2 - Riverton Creek Flapgate Removal with OTAKCity of Tukwila
Public Works Department - Henry Hash, Director
INFORMATIONAL MEMORANDUM
TO: Transportation and Infrastructure Committee
FROM: Henry Hash, Public Works Director //'//-
BY: Mike Perfetti, Habitat Project Manager
DATE: September 7, 2018
SUBJECT: Surface Water Fund - Riverton Creek Flapgate Removal Project
Project Number 99830103
Contract 17-070, Amendment No. 2
ISSUE
Approve Amendment No. 2 to Contract No. 17-070 with OTAK, Inc.
Allan Ekberg, Mayor
BACKGROUND
In May 2017, the City entered into a consultant agreement with OTAK, Inc. for design and permitting services for the Riverton
Creek Flapgate Removal Project. This project will increase salmonid accessibility to rearing habitat in Riverton Creek by removing
two culverts and flap gates at the mouth of the creek and replacing a section of at -grade trail with a bridge over the restored open
channel.
DISCUSSION
Under the original scope of work, Otak performed a review of the previous design work (Berger ABAM, 2009), and found that on -
site geotechnical evaluation, cultural resources, and hydraulic modeling and scour analysis had not been provided, though stability
concerns had been documented.
OTAK's Amendment No. 1 added geotechnical services and some additional scope to revise the channel section to address long-
term stability concerns. As a result, the team is recommending that a second row of tie -back anchors be installed in the existing
sheet pile wall (supporting Tukwila International Blvd.), and a new, taller soldier pile wall be installed on the east side of the
channel to minimize disturbance and excavation of the existing soils and parking lot. After a constructability review, the team also
recommends revising the construction sequencing shown in the 2009 design in order to reduce the risk for mobilization of
sediment into the Duwamish River during channel excavation. Sediment mobilization will likely be a concern to the environmental
reviewing agencies.
The proposed Amendment No. 2 will incorporate current findings and recommendations into final design and bid documents that
will include the realigned creek channel, improved sheet pile wall design, improved construction sequencing, and services to
support the City in addressing permit agency comments.
FISCAL IMPACT
Amendment No. 2 is for $37,064.00, bringing the total contract amount to $182,420. To fund Amendment No. 2, the project will
utilize remaining 2018 CIP surface water design funds and the 2019 design budget, then be partially or wholly reimbursed through
the 2017 SRFB design and construction grant of $846,965.00 (The match requirement is $149,465.).
Agreement 2018/2019 Budget
Original OTAK Contract + Amendment No. 1 $ 145,356.00 $ 145,356.00
OTAK Amendment No. 2 37,064.00 40,730.00
$182 420.00 $186.086.00
RECOMMENDATION
Council is being asked to approve design Amendment No. 2 for $37,064.00 with OTAK, Inc. for the Riverton Creek Flapgate
Removal Project and consider this item on the Consent Agenda at the September 17, 2018 Regular Meeting.
Attachments: Page 93, Proposed 2019 —2024 CIP
OTAK Supplemental Agreement #2
33
W:1PW Eng1PROJECTSIA- DR Projects\Riverton Flap Gate Removal (99830103 98-DR03)1Consultant SelectionlPhase 21contracllAmendment#211nfo Memo Otak PE Amend #2 2018081091.docx
CITY OF TUKWILA CAPITAL PROJECT SUMMARY
2019 to 2024
PROJECT: Riverton Creek Flap Gate Removal Project No. 99830103
Remove two culverts and flap gates at Duwamish River; install pipe arch, create open channel
DESCRIPTION: confluence, install trail bridge over new channel, restore/revegetate 200 feet of creek channel and
450 ft. of pond shoreline.
JUSTIFICATION: Increase available salmonid rearing habitat and increase flood refuge in lower Duwamish River.
Improve fish access to Riverton Creek and enhance salmon rearing and resting area.
STATUS: Design underway in 2018. Construction grant of $846k from WA State RCO.
MAINT. IMPACT: Expected to increase maintenance.
COMMENT:
Project used as mitigation for East Marginal Way Pipe Replacement Project and HPA
Control #133763-1 requires work to be completed by June 11, 2019, which will need to be extended.
FINANCIAL Through Estimated
(in $000's)
2017 2018 2019
2020 2021 2022 2023 2024 BEYOND TOTAL
EXPENSES
Design
204
100
40
344
Land (R/W)
0
Monitoring
15
15
15
15
15
15
90
Const. Mgmt.
184
184
Construction
918
918
TOTAL EXPENSES
204
100
1,142
15
15
15
15
15
15
1,536
FUND SOURCES
Awarded Grant
72
847
919
Proposed Grant
0
Mitigation Actual
0
Mitigation Expected
0
Utility Revenue
132
100
295
15
15
15
15
15
15
617
TOTAL SOURCES
204
100
1,142
15
15
15
15
15
15
1,536
2019 - 2024 Capital Improvement Program
93
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Exhibit A-2
Scope of Work
Riverton Creek Flapgate Removal Project
City of Tukwila
August 7, 20I 8
Otak Project No. 32740
Amendment No. 2
A 75-percent design for the Riverton Creek Flapgate Removal Project was completed previously by
a different consultant. Under the original Scope of Work, Otak performed an Intake Review of the
previous design and found that on -site geotechnical evaluation, cultural resources, and hydraulic
modeling and scour analysis had not been provided with the previous design, even though stability
concerns had been documented. Further, based on a site investigation of existing conditions, Otak's
team recommended that the proposed channel section be revised to address slope stability and
erosion concerns.
The previous Amendment No. 1 added geotechnical services and some additional scope to revise
the channel section to address long-term stability concerns. Once on -site geotechnical explorations
and analysis were performed, the team met to review the geotechnical recommendations and identify
necessary measures to address global stability, since, the adjacent Tukwila International Blvd. bridge
abutment sheet pile wall and private parking lot will be supported by the proposed channel side
slopes after flapgate and culvert removal and breaching of the revetment. Options considered
included further stabilization measures for the existing sheet pile wall such as a new sheet pile wall at
the base of the existing wall or the installation of a lower row of tie -back anchors nearer the base of
existing wall. Options for a new retaining wall along the east side of the channel were also
considered to maintain the existing private parking lot. Constructability and cost were compared
between optional design elements for stabilization.
In addition to the channel alignment and pedestrian bridge being shifted east, further away from the
existing sheet pile wall, the team recommends that a second row of tie -back anchors be installed in
the existing sheet pile wall, and a new, taller soldier pile wall be installed on the east side of the
channel to minimize disturbance and excavation of the existing soils and parking lot. After
constructability review, the team also recommends revising the construction sequencing shown in
the 75% design by others in order to reduce the risk for mobilization of sediment into the
Duwamish River during channel excavation. Sediment mobilization will likely be a concern to the
environment review agencies. The recommended revisions to the previous design and the addition
of new stabilization elements are beyond the final design scope. At the request of the City, Otak
also met with WSDOT in the field to review the project and a general permit will be required from
the WSDOT Local Agency and Development Services group. They have requested to review all
35
Exhibit A-1 Scope of Work
Continued
technical analysis including the geotechnical report, hydraulic analysis, and structural calculations.
Coordination with WSDOT and permitting support services to address comments are beyond the
permitting support scope.
The following scope is for additional final design services for the recommended stabilization
measures based on the geotechnical analysis and additional services to support the City in addressing
comments from permitting agencies. This scope also provides additional services for preparation of
final bid documents which was removed in Amendment No. 1.
The following table provides a summary of the contract value for the project as modified by
Amendment No. 2.
Contract
Authorized Fee
Original Contract
$105,363.00
Amendment No. 1
$39,993.00
Amendment No. 2
$37,064.00
Total
$182,420.00
Scope and Budget Modifications
1.1 Project Management and Coordination
The scope for this task is increased to provide project management and coordination for an
extended project schedule for anticipated construction in 2019. This includes additional services for
regular status update meetings with the City, project management, and preparation of project reports
and invoices.
4.1 JARPA Preparation
The scope for this task was reduced with Amendment No.1. The scope for this task is increased to
provide services for development of grading quantities to be included in the Joint Aquatic Resources
Permit Application (JARPA) being prepared by the City. The quantities will include the revised
construction sequencing of the culvert removal and revetment grading. Otak will also provide the
project summary narrative via email for the JARPA.
4.7 Permitting Support
The scope for this task was reduced with Amendment No. 1. This scope provides services for
developing responses to comments received during review of permit submittals. The scope for this
W:\PW Eng\OTHER \Mike Perfetti\ temp \ Riverton Creek Flapgate\Riverton SOW Amend 2_18_0807.docx 2
36
Exhibit A-1 Scope of Work
Continued
task is increased to include one round of comment response for the JARPA and one round of
comment response for the WSDOT General Permit.
Task 5 — Final Design
5.1 Final Design and Plan Sheets
4 Creek Grading, Trail Restoration, and Bank Armoring Design
The scope for this task is increased to include final design of the following elements:
1. Revised channel alignment and section to allow 2:1 channel side slopes.
2. Revised bridge location and existing concrete wall demo and tie-in extents to align with
revised channel location.
3. Additional row of tie -back anchors in the lower portion of the existing sheet pile wall.
4. Revised construction sequencing shown in the plans to reduce the potential for in -water
work and to minimize sediment mobilization during culvert removal and channel grading
activities.
6 Retaining Wall Design (3 sheets)
This scope is increased to include final design of a solider pile wall east of the proposed channel
with greater vertical and horizontal extents.
5.2 Specifications
Otak will provide final bid -ready General Special Provisions (GSP) and project -specific Special
Provisions for Divisions 2 — 9, excluding the landscape and planting Special Provisions to be
prepared by the City per Amendment No. 1 scope.
Per Amendment No. 1 scope, The City will prepare Division 1 of the Specifications and compile the
master Contract Manual including all Contract and Bid Forms, Amendments to the WSDOT
Standard Specifications, and Appendices. The City will incorporate Special Provisions provided by
Otak.
5.3 Construction Cost Estimates
Otak will prepare a final Engineer's Estimate for construction.
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Exhibit A-1 Scope of Work
Continued
Deliverables:
1. Final bid -ready Special Provisions Division 2-9 in MS Word format
2. Final full-size signed Bid Plans
3. Final Engineer's Estimate
4. Comment Responses to permitting agencies provided via email
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Exhibit B-2 - Fee Estimate
City of Tukwila - Riverton Creek Flapgate Removal Project
Otak, Inc., Project 32740
AMENDMENT NO. 2, 8/7/18
Task
Description
I
Proj. Mo t./Design
Structural
Environmental
Resource
CADD
Admix
Total Hours
(Otak)
Total Fee by Task
(Otak)
Geotech
Cultural
Total Fee (Team)
Sr. PIC /
Sr. PM Civil
CE VI / Proj.
Mgr.
E
P.„ V
v
v
v
Engineering
Tech IV
Project Ado in
Assistant
Otak Direct
Costs
Geo
Engineers
Task 1
Project Management
2
16
18
$ 2,628
$ 2,628
1.1
Project Management and Coordination
2
16
18
$2,628
Task 4
Permitting, Environmental Review and Coordination
14
4
2
4
4
2
8
38
$ 4,936
$ 4,936
4.1
JARPA Preparation
8
2
4
2
8
24
$2,839
4.7
Permitting Support
6
4
4
14
$2,097
Task 5
Final Design
52
44
78
54
32
8
268
$ 29,500
$ 29,500
5.1
Final Design and Plan Sheets
4. Creek Grading, Trail Restoration, and Bank Armoring Design
40
30
60
40
24
194
$21,545
Final PSE Bid Set
6
8
16
6
8
44
$4,738
5.2
Specifications
Final PSE Bid Set
4
4
4
8
20
$2,052
5.3
Construction Cost Estimates
Final PSE Bid Set
2
2
2
4
10
$1,165
Project Total Hours
2
82
4
46
82
4
2
62
32
8
324
Billing Rate (including OH and Profit)
$234.60
$134.90
$189.16
$131.97
$104.10
$132.67
$117.30
$105.59
$71.67
$70.15
Total Labor Cost including Overhead and Profit
$ 470
$ 11,062
$ 757
$ 6,071
$ 8,536
$ 531
$ 235
$ 6,547
$ 2,294
$ 562
$ 37,064
$ -
$ -
$ 37,064
Direct Expenses
$ -
$ -
Project Total (Amendment No. 2)
I
$ 37,064
$ -
$ -
$ -
$ 37,064
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