HomeMy WebLinkAbout7A2 - Bridge over Wonderland Creek GreenwayDO NOT REMOVE -
Memorandum PRAB File Matenal
~„^ DATE: October 5, 2000
~"~ TO: Parks and Recreation Advisory Boazd members
FROM: Chris Dropinski, Director of Pazks and Recreation
Sazah DeSouza, City Liaison Contract Manager
Teresa Grills and Diana Royce Smith, City Liaison Office
RE: Bridge over Wonderland Creek Greenway Change Order for Bridge vs __
Low Water Crossing in Phase 1
PURPOSE:
Update the Boazd on the proposal from Public Works Department to change order a low-
water crossing to a temporary bridge in the Wonderland Creek alignment in the Valmont
City Park Phase 1 area and request feedback from the Board
BACKGROUND
Construction documents for Phase One at Valmont City Pazk include putting a low-water
crossing sttucture over Wonderland Creek Greenway The Site Review and Concept
Plans show a much more expensive well-designed permanent bridge crossing designed to
~, hold emergency vehicular traffic and the proposed multi-use/cycling path ttaffic. The
~,,,,, low-water crossing is understood to be a temporary structure developed in Phase One that
was chosen primarily due to budgetary constraints, with the idea that the permanent
bndge structure v~nll be a future partnered expense. The costs for the low-water crossing
have been estimated at approximately $10,000, budgeted within Phase One
The permanent bridge is currently estamated at $391,600, by Kate Bernhazdt for the
Cycling group at 27' wide, 50 ft. long, including rock retaining walls, railing, load
capacity for trucks, including design and conhngency The Cycling Group has received a
"Letter of InteresY' for partnering and is cunently preparing their formal proposal which
will include the~r efforts to pursue fundraising to cover all project costs, including the
permanent bndge '
There have been many conversations regazding the upgrade of the proposed low-water
crossing to a bridge Boulder Nordic Club (BNC) has previously asked that an upgrade
be made during Phase One construction to allow for pedestrian and skiing traffic under a
temporary bridge and over the Greenway traffic Gary Lacy, the engineer under conuact
to the Public Works Department, and also the designated spokesperson for BNC, has
pursued several avenues and altematrves to try and find a way to make this happen
Other alternatives, including proposals in conjunction with the Transportation
Department, have previously been deemed mappropriate
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'~' ~-' ~ ~"'RecenYly; ~N~ has been working with Annie Noble from Public Works. Attached is an
, email from her, outlining her support for an upgrade to a temporary bridge instead of a
~~` .,~~ ~ low-water crossing In summary, Public Works has proposed to pay for the upgrade to a
10-foot wide bridge that would allow for tr~c on and below the bridge over the
Wonderland Creek Greenway This bridge would still be viewed as a temporary bridge, ^-
assuming that eventually the proposed 27-foot bridge will be put in Neither this
temporary bridge nor the low-water crossing meets proposed design guidelines for bridge
structures for the pazk The temporary bridge is a Continental Bridge, commonly used on
City greenways and paths, and can be removed and relocated to another site when the
permanent bridge goes in Public Works has proposed to fund the upgrade, with Pazks
and Recreation contributing the $10,000 funding previously budgeted for the low-water
crossing
This change order would be regazded as outside the scope of Phase One construction and,
as such, the City Liaison Office would be mvolved m the relationship and of ttus work
Public Works proposes to mclude this upgrade as a"Change Order" to their conuact wuh
Wycon and handle the costs and oversight for design and construction documents for the
change
Advantages for this proposal
1 Elimination of the need to take out dirt down to the grading lme necessary for the
low-water crossing, and then later refill the dirt to a gade similaz to the e~cisting gade
when the permanent bridge goes in (Estimated at 1100 cu yd of dirt)
2 Create less discuprion to Wonderland Creek and the adjacent path.
3 Provide sepazation between users of the Greenways path and the Pazks soft surface
path developed in Phase One
4 Upgrade proposal does not include rerouting Goose Creek concrete path traffic ~
through the pazk near the proposed group picnic azea. ~
5 Bridge can be reused for other projects upon removal
6 Grading costs will be lower for partnered permanent bridge
7 Net costs for Parks and Recreation Deparunent aze identical
8 New proposal removes BNC from partnering for upgrade
9 Change done in conjunction with Phase One and Wonderland Creek construction
provides an overall cost saving
10 Provides another positive relationship between a Public Works/Pazks project, with
Public Works proposing to fund the upgrade and oversee the changes and
construction
Disadvantages:
1 May disrupt current planning for Phase One
2 May require additional time resources from McLaughlm (being used for Phase One
and Public Works, this additional time would be funded by Public Works)
3 Additional concerns aze currently being sought
At this point, it appears that the advantages of going forwud with the upgrade to the
temporary bridge outweigh the disadvantages However, if this upgrade is going to occur
congruent with Phase One and Wonderland Creek construction, the decision needs to be
made expediently
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WONDERLAND CREEK BRIDGE AT VALMONT CITY PARK
COST ESTINfATE
Temporary Bndge Upgrade vs Low Water Crossing
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1. 45' long, by 10' wide bike/pedestrian bridge (10,000# loading) ' $20,500
2. Concrete abutments (6 5 cu.yd each) x 2 x$300 00 $3,900
3. Bridge setting (lump sum) $1,000
4. General site grading, excavation, bac~ll, & re-seeding
(included within Wonderland Creek Greenway Project,
-approx net savings of 1100 cu yd of fill)
SUBTOTAL $25,400
Approx. credit for not building low-water crossmg and ($10,000)
related grading
TOTAL
Public Works contribution for a temporary bndge $15,400
Eshmate provrded by Boulder Nordre Club, Gary Lacy, Engrneer
Rev:ewed by Anrae Noble, Pubkc Works
Ocfober 2, 2000
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