HomeMy WebLinkAbout031025-03.4 Diablo Trail PresentationDIABLO ROAD TRAIL PROJECT
Danville Town Council & Town
Commissions 2025 Annual Workshop
Project Status Update
March 10, 2025
A TRAIL 3 DECADES IN THE MAKING
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A long-term vision to close a trail gap identified in the Danville Townwide Trail Plan (1989)
DIABLO ROAD
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PROJECT
OVERVIEW
•Purpose: Closes the gap between the
Barbara Hale Trail and Mount Diablo
State Park, enhancing connectivity
and outdoor access.
•Challenges: One of the most difficult
segments to build due to creek
crossings, hilly terrain, and need for
access across private lands.
•Opportunity: Made possible through
approval of the Magee Preserve
project, which preserved 93% of the
410-acre site for open space and
trails. The developer was required to
build the eastern segment and grant
a public easement for the Town to
construct the western segment.
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PROJECT TIMELINE
•1989 – Danville Townwide Trail Plan
adopted to address public need
•2019 - Secured public access through
Magee Preserve project approval
•2019-2022 – Completed conceptual
engineering design and
environmental assessment
•Early 2023 – Winter storms caused
culvert collapse and creek bank loss,
impacting trail alignment
•2023-2024 – New field surveys,
engineering re-design, and extended
regulatory permit review
•Early 2025 – Permits secured; trail
preparation begins starting with tree
removal along Diablo Road
•Spring - Summer 2025 – Bid process
and Phase 1 construction to begin
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TRAIL DESIGN
ELEMENTS
•Total Completed Length: 2.1 miles
Existing (0.5 miles) + Town segment (0.9
miles) + Developer segment (0.7 miles)
•Alignment (Town segment): South
side of Diablo Road
•Connects Existing trail (to the west)
with developer-constructed trail (to
the east)
•Crossing: Diablo Road @ Fairway
Drive
•8-foot-wide paved multi-purpose
pathway with 2-foot gravel
shoulders
•Pathway separated 4-5 feet from
Diablo Road with physical barrier
TWO-PART CONSTRUCTION
Easterly section completed by the developer, as part of the Magee Preserve subdivision
Westerly section will be constructed by the Town, connecting to Barbara Hale Trail (existing)
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Athenian
SchoolGreen Valley
Elementary
School
Road
Developer-built
Segment
(0.7 miles)
Town Segment
(0.9 miles)
Existing Trail
Segment (0.5 miles)
Diablo Road
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PROJECT COST
UPDATES
Pre-Covid Engineer’s Estimate
(total project cost):
$5.69 million
Updated 2025 Engineer’s Estimate
(total project cost):
$7.15 million
Costs increases due to:
•New Bioretention Requirements
(RWQCB and CDFW permits)
•Slope Stability and Drainage
(additional retaining walls for slope
erosion, result of winter storms)
•Inflationary impacts
$0.59M
$6.06M
$0.50M
Approx. $7.15M
THANK YOU
QUESTIONS?
Developer
constructed
segment
Town
constructed
segment
DIABLO ROAD TRAIL ALIGNMENT & CROSSING
Aerial View: Looking South
Trail Crossing