HomeMy WebLinkAbout07 July 2012 spec meeting packetAll times are subject to variation without notice
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AGENDA
Special Meeting of the Pitkin County Healthy Rivers and
Streams Citizens Advisory Board
To be held telephonically
July 5, 2012 – 10:00 a.m.
Dial-in instructions for telephonic Special Meeting of the Healthy
Rivers and Streams Board
Date and Time: July 5, 2012 10 a.m. mst
US Toll-Free Number: (855) 212-0212
Meeting ID: 791-206-934
Jul 05 2012 10:00 AM (US/Mountain)
https://www.startmeeting.com/wall/791-206-934
Instructions:
At the scheduled date and time of the meeting, dial into the
conference line using the toll-free number 855-212-0212
When prompted, enter the meeting ID 791-206-934, followed by the
pound key.
10:00 a.m.
Roaring Fork Conservancy
Coal Creek Funding Request
Sharon Clarke
Roaring Fork
Conservancy
Rio Grande Park Stormwater
Improvements Funding Request
Stephen
Ellsperman -
City of Aspen
Director of Parks
and Open Space
Request for Proposal for the study of the
relationship between the value of the
residential real estate in Pitkin County and
the Roaring Fork River
John Ely
1
AGENDA ITEM SUMMARY
July 5, 2012
TO: River Board
FROM: John Ely
SUBJECT: Miller Ecological Consultants Report
Excerpts on John Denver Sanctuary/Kayak Park
At the June 21, 2012 meeting, the topic of the John Denver Sanctuary/Kayak Park was
discussed during the of the City of Aspen’s Rio Grande Park Stormwater Improvements
Funding Request.
Below are excerpts from the Final Report of Miller Ecological Consultants on the Evaluation of River Health - Roaring Fork River near Aspen, CO regarding the John
Denver Sanctuary/Kayak Park. This was a study approved by the River Board in 2010
and funded by the Healthy Rivers and Streams Program.
For Miller’s complete report, Roaring Fork River Health Study click here.
Page iii
The kayak park upstream of the Aspen Art Museum also impacts natural river channel
function. We recommend the complete removal of the course and reclamation of the area occupied by the course to a functional floodplain. Based on our knowledge of the course, it appears that the course is used infrequently and only when there is sufficient flow, such
as during spring runoff.
Thus, the course is only viable for a short period during the entire year and will likely
require ongoing maintenance to keep the course pools clear of sediment and organic debris. The fine sediment and slow velocities at low flows are excellent habitat for tubifex worms that can host whirling disease. Removal of the course would remove this
habitat from the river. The kayak channel could be reclaimed by removing the excavated
material from the intervening island and refilling the kayak channel with little to no effect
on in-stream habitat on the main channel of the river. By refilling the kayak channel, the floodplain area occupied by the island that was covered with the material previously
excavated from the kayak channel would also be restored. Reshaping of the left bank of
the river and replanting riparian vegetation on the reclaimed island/floodplain area would
also contribute to habitat diversity in this reach.
2
Page 28 Three man-made channels were also documented. These primarily impact the river by
diverting flow from the main channel. The most problematic of the three is the kayak
course at the John Denver Sanctuary, which contains seven pools and eight boulder drop
structures. At high or moderate flows, fish may migrate or get diverted into the course. Then, once flows recede, fish can become trapped in the pools, which was observed during the site visit.
Appendix E Geomorphology Report Assessment by Ayers Associates Page 105
(Page 16 of report) There are a number of potential problems associated with the kayak course that impact river function. First, the course diverts flow from the main channel for its use. Since the
width of the main channel through this reach has been maintained, the flow diversion into
the kayak course results in shallower flows in the main channel during low to moderate
flows. Second, the reduced flows in the main channel can also result in fine grained sediment deposition, which may limit the availability of spawning substrate. Also, during higher spring flows, a significant amount of sediment eroded from the unprotected banks
of the kayak course as well as sediment transported in from the main channel is deposited
in the pools of the course. Deposition of fine sediment within the pools as well as the
trapping and deposition of organic materials may limit the viability of the course if not regularly removed. Finally, there are boulder drop structures at both ends of the course with the downstream structure having a drop of about 3.5-4 feet and the upstream
structure having a 1-1.5 foot drop. These upper and lower structures create an obstruction
to fish passage during low flows. During the moderate to high flows, fish may migrate or
be diverted into the kayak channel and can become trapped in the pools once flows recede (this was readily evident during our site visit). The sediment and organic material deposition in the pools, the limited habitat, and potential summer heating
of the water in the pools can be detrimental to any fish stranded in the kayak channel
during the summer months.
Appendix E Geomorphology Report Assessment by Ayers Associates Page 105 (Page 23 of report)
With regard to the kayak park at the John Denver Sanctuary, we would recommend the
complete removal of the course and reclamation of the area occupied by the course to a
functional floodplain. Based on our knowledge of the course, it appears that the course is used infrequently and only when there is sufficient flow, such as during spring runoff.
Thus, the course is only viable for a short period during the entire year and will likely
require ongoing maintenance to keep the course pools clear of sediment and organic
debris. The kayak channel could be reclaimed by removing the excavated material from
the intervening island and refilling the kayak channel with little to no effect on in-stream habitat on the main channel of the river. By refilling the kayak channel, the floodplain
area occupied by the island that was covered with the material previously excavated from
the kayak channel would also be restored. Reshaping of the left bank of the river and
replanting riparian vegetation on the reclaimed island/floodplain area would also
contribute to habitat diversity in this reach.
Page 1 of 2
MEMORANDUM
TO: Pitkin County Healthy Streams & Rivers Board
FROM: Scott Chism, Planning & Construction Manager,
City of Aspen Parks Department
April Long, Stormwater Manager
City of Aspen Engineering Department
THRU: Stephen Ellsperman, Parks and Open Space Director
City of Aspen Parks Department
DATE OF MEMO: June 15, 2012
MEETING DATE: June 21, 2012
RE: Rio Grande Park Stormwater Improvements Funding
CC:
REQUEST OF BOARD: The City of Aspen Parks and Engineering Departments would like
the Healthy Streams and Rivers Board to consider a $43,000 financial partnership in the
construction of Phase 2 of the Rio Grande Park Stormwater Improvements Project. (See
Attachment A, Phase 2 Design Character Sketches, Attachment C, Park Site Plan)
BACKGROUND: The City of Aspen has made a strong commitment to environmental
initiatives, including managing stormwater. City Council has directed staff to implement long-
term solutions to ensure that the community is responsible for clean stormwater discharge into
the Roaring Fork Watershed. An equally important goal has been to enhance the ecological
integrity of areas where stormwater improvements are proposed.
Stormwater from the central core of the city and Aspen Mountain currently discharges into the
Roaring Fork River from three major drainages. One of the three drainages (‘East Drainage’)
flows from the street gutters and into Rio Grande Park near the Rio Grande Recycle Center
before reaching the river. Another of the three drainages (‘Central Drainage’) flows under Mill
Street to directly discharge into the river. The third major drainage (‘West Drainage’) flows into
the Jennie Adair Wetlands to allow for water quality enhancement and flood control before
discharging into the river. The stormwater conveyance effort currently underway at Rio Grande
Park follows the successful stormwater conveyance redevelopment the City completed in 2006 at
the Jennie Adair Wetlands.
Site work at Rio Grande Park was initiated in early 2011 in association with redevelopment of
the Theatre Aspen theatre tent and has been divided into two phases. Both phases of proposed
improvements have a similar design character to what was created at the Jennie Adair Wetlands.
Page 2 of 2
A comprehensive project budget of $1.175 million has been established to complete both phases
of the proposed environmental and stormwater enhancements at Rio Grande Park. The
comprehensive budget includes costs for a proposed public restroom building, irrigation pump
house and infrastructure and a pre-sedimentation treatment vault adjacent to North Mill Street.
DISCUSSION: The new sequence of stormwater wetland ponds will capture, cleanse and
highlight storm water within the park from both the ‘East Drainage’ and ‘Central Drainage’
before it reaches the Roaring Fork River. (Attachment B, Storm Water Flow Diagram,
Attachment C, Park Site Plan). Phase 1 improvements are scheduled to be completed by early
July 2012 and Phase 2 improvements are scheduled to be completed by early June 2013, with the
majority of Phase 2 improvements complete by fall 2012.
Specific elements that are being integrated for stormwater improvements include diverse
wetlands, a sand infiltration system similar to a river ‘bench’, biofiltration swales, water quality
finishing ponds, drop structures made of natural materials and a pre-sedimentation treatment
vault. These stormwater practices will provide both water quality improvements with an
enhanced park experience and also serve as a showcase of stormwater treatment options to be
admired and replicated by other mountain resort communities.
This project has great partnership potential for the Pitkin County Healthy Streams and Rivers
Board relative to a water quality improvement effort in Pitkin County. A financial partnership
between the City of Aspen and the Pitkin County Healthy Streams and Rivers Board would be
exciting and enable further enhancements to the planned biofiltration swales and water quality
finishing ponds being developed for the Mill Street/‘Central Drainage’) flows that have a shorter
treatment sequence through the park. The shorter treatment sequence in comparison to the ‘East
Drainage’ also passing through the park means that every opportunity to improve water quality
within the available area that is suitable in a park environment would ideally be maximized.
Another opportunity would include more extensive interpretation of the benefit to the river’s
water quality as a result of the project.
The $43,000 financial partnership request for this project is based on some anticipated strain on
the current budget from the necessary infrastructure costs associated with the pre-sedimentation
treatment vault and proposed stormwater interpretation elements along the Mill Street/‘Central
Drainage’ area described above (Attachment C, Park Site Plan). Difficult choices relative to
implementing all of the proposed water quality features envisioned for that area are very possible
without other financial partners to fully realize this very important project for river health of the
upper Roaring Fork River. City staff looks forward to collaborating with the Pitkin County
Healthy Streams and Rivers Board.
ATTACHMENTS:
Attachment A – Phase 2 Design Character Sketches (x2)
Attachment B – Stormwater Flow Diagram
Attachment C – Park Site Plan
Attachment D – Cost Estimate: $43,000 partnership request
ATTACHMENT D
RIO GRANDE PARK PHASE 2 SITE : PitCo Healthy Streams & Rivers Partnership
Project Budget / Estimated Construction Costs Aspen Parks Department
15-Jun-12
WORK ITEM QTY UNIT UNIT COST TOTAL COST
SITE CONSTRUCTION: COA scope
Unclassified Excavation: Pond 7 and lower 1 LS 17,493.00 17,493.00
biofiltration swale for N. Mill drainage
(16 days Parks Construction Crew)
Biofiltration Swale materials for lower
N. Mill drainage area
Seed 5,475 SF 0.08 438.00
(5,475 s.f.)
Native Area Mulching (straw mulch)5,475 SF 0.10 547.50
(5.475 s.f.)
Native Area Mulching (hydromulch)5,475 SF 0.25 1,368.75
(5,475 s.f.)
Wetland Plantings 5,475 SF 1.04 5,694.00
(5,475 s.f.)
Plant Materials (trees, shrubs)1 Allow 3,500.00 3,500.00
Trucking: boulders, fill, cobble, sand materia 1 LS 2,400.00 2,400.00
for lower Biofiltration Swale
Landscape Restoration 1 LS 11,892.00 11,892.00
(7 days Parks Restoration Crew)
Subtotal 43,333.25
Total Rio Grande Park Ph 2 Site: PitCo HSRB Partnership 43,333.25