Template revised September 22, 2016.
COMMISSION
AGENDA MEMORANDUM
Item No.
6d_Attach_B
ACTION ITEM
Date of Meeting
November 14, 2017
DATE: November 7, 2017
Attachment B
SUBJECT: Shilshole Bay Marina Paving (CIP #C800355)
EXECUTIVE SUMMARY
The work consists of pavement replacement and/or overlay to address failed or failing areas
along the entire length of the parking lot that were not replaced or rehabilitated during the
2005-2008 capital redevelopment of the Marina site.
The current condition of the pavement throughout much of the site is poor, including some
localized failed areas which will be entirely replaced. The majority of the site will be ground
and overlaid with a 2.5 inch overlay of asphalt pavement, then restriped.
A significant portion of the replaced asphalt section will be pervious pavement, allowing surface
water to drain directly into the ground rather than through traditional stormwater conveyance
methods and eventually to the Puget Sound. Staff is also proposing the introduction of similar
pervious strips of pavement throughout the site to test the efficacy of this type of system in
intercepting stormwater before it enters the catch basin system. These will be 4 foot wide
strips between the head to head parking areas along the site.
Cost estimates have increased since initial scoping due to progressing deterioration leading to
larger areas of reconstruction than anticipated and increased construction pricing in the
market.
JUSTIFICATION
In November 2013, the Port commissioned an evaluation of the current pavement condition at
Shilshole Bay Marina by Pavement Consultants Inc. The study was undertaken to assess the
condition of the parking lot pavements at Shilshole Bay Marina and to identify strategies for
improving condition and extending pavement life. The condition assessment included three
field investigation tasks: a visual inspection of the pavement surface, non-destructive deflection
testing and geotechnical investigation. This study found that in general most of the pavement
is structurally sound even though the asphalt exhibits significant cracking and surface
irregularities.
Based on the evaluation results, several feasible repair alternatives were investigated. They
would extend the life of the pavement between 5 and 40 years. The recommended alternative,
COMMISSION AGENDA – Action Item No. 6d_Attach_B Page 2 of 5
Meeting Date: November 14, 2017
Template revised September 22, 2016; format updates October 19, 2016.
which provides a 20 year design life, encompassed dig-out and replacement of pavement near
some catch basins and a 2.5 inch asphalt overlay in other affected areas.
This work will significantly extend the life of the paving at Shilshole Bay Marina, while also
improving its environmental performance by incorporating pervious pavement sections in non-
traffic bearing areas.
DETAILS
The replacement and overlay improvements proposed will extend the life of the parking lot
pavement for 20 years, or more
Scope of Work
The scope of work consists of full depth replacement of failed areas of asphalt pavement, edge
grinding and a 2.5 inch overlay of other areas and full restriping of the parking areas. No
significant changes to the traffic flow, islands or channelization are planned as part of this work.
The parking areas will retain the current angled parking configuration, which is the tenants’
strong preference as expressed at public meetings and open houses.
The work will also include areas of pervious pavement, both in fully reconstructed areas, and
along the parking strips where the vehicles meet bumper to bumper. This pavement, along
with a new stormwater filtration system at the north end of the parking area, not only satisfies
stormwater requirements but provides additional storm water treatment of parking lot runoff.
Small Business
The project team will coordinate with the small business group to maximize opportunities for
small business participation either as direct contracts or through subcontract opportunities.
Schedule
Paving work is seasonal and generally should be completed before mid-October. Phasing
language is being incorporated in the contract documents to limit the disruption to parking and
ongoing marina operations during construction, allowing for no more than 200 parking stalls to
be affected at any given time. Staff will work with the contractor to give as much advance
warning of any closures to tenants as possible.
Activity
Design start
January 2016
Commission construction authorization
November 2018
Construction start
June 2018
In-use date
December 2018
COMMISSION AGENDA – Action Item No. 6d_Attach_B Page 3 of 5
Meeting Date: November 14, 2017
Template revised September 22, 2016; format updates October 19, 2016.
Cost Breakdown
Total Project
Design
$0
$ 250,000
Construction
$1,750,000
$1,750,000
Total
$1,750,000
$2,000,000
ALTERNATIVES AND IMPLICATIONS CONSIDERED:
Alternative 1 - Continue to use the pavement in its current deteriorated condition.
Cost Implications: Some areas of the parking lot would still need immediate attention
(~$200K), but the remainder could continue to be serviceable in the short term. Subsequent
rehabilitation costs would be as shown in alternatives below, but adjusted upwards for market
changes.
Pros:
(1) Lowest initial cost. No capital funding required and leaves capital funds available for
other projects.
Cons:
(1) Some areas currently failing would continue to ravel, increasing the work to be
performed later.
(2) Pervious pavement improvements are currently tied to the restroom development
and would need to be incorporated or mitigated elsewhere.
This is not the recommended alternative.
Alternative 2 - Minimal upgrades, seal coat and thin the overlay areas to 2”, remove pervious
paving except where required
Cost Implications: $1,700,000
Pros:
(1) Will extend the life of the paving by ~10-15 years.
Cons:
(1) Still requires full cost of striping all affected areas.
(2) Lower life expectancy compared to thicker overlay option.
(3) Pervious pavement areas would still need to be incorporated to address stormwater
requirements of new paving.
This is not the recommended alternative
Alternative 3: - Overlay and rehabilitation of all areas outside of the previously improved areas
Cost Implications: $2,000,000
COMMISSION AGENDA – Action Item No. 6d_Attach_B Page 4 of 5
Meeting Date: November 14, 2017
Template revised September 22, 2016; format updates October 19, 2016.
Pros:
(1) Longest life alternative; will provide additional 20-25 year life on existing paving
areas.
(2) All stormwater requirements met plus additional storm water treatment of parking
lot runoff
Cons:
(1) Higher initial cost.
This is the recommended alternative
FINANCIAL IMPLICATIONS
Cost Estimate/Authorization Summary
Capital
Expense
Total
COST ESTIMATE
Original estimate
$1,914,000
$0
$1,914,000
Current change
$ 86,000
0
$ 86,000
Revised estimate
$2,000,000
0
$2,000,000
AUTHORIZATION
Previous authorizations
$ 250,000
0
$ 250,000
Current request for authorization
$1,750,000
0
$1,750,000
Total authorizations, including this request
$2,000,000
0
$2,000,000
Remaining amount to be authorized
$0
$0
$0
Annual Budget Status and Source of Funds
This project was included in the 2017 Plan of Finance under CIP #C800355 SBM Paving with a
total cost of $1,196,000. The additional $804,000 required to fund this project is available
under CIP #C800002 MD: Contingency Renewal & Replace. The increase in estimate is due to
refinement of scope and increasing prices in the Seattle construction market.
This project will be funded by the General Fund.
Financial Analysis and Summary
Project cost for analysis
$2,000,000
Business Unit (BU)
Recreational Boating
Effect on business performance
(NOI after depreciation)
This project will support/maintain current moorage
revenue at SBM. Incremental depreciation expense from
this project is estimated at $100,000 per year, based on a
20-year asset life. NOI after Depreciation will decrease
by the associated depreciation from this project.
COMMISSION AGENDA – Action Item No. 6d_Attach_B Page 5 of 5
Meeting Date: November 14, 2017
Template revised September 22, 2016; format updates October 19, 2016.
IRR/NPV (if relevant)
The NPV is present value of the project cost
CPE Impact
N/A
Future Revenues and Expenses (Total cost of ownership)
No future revenues are anticipated as a result of this paving project.
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS
None