06.12.13 slacklining update
MEMORANDUM
TO:Open SpaceBoard of Trustees
FROM:Michael D. Patton, Director
Mark D. Gershman, Environmental Planning Supervisor
Kacey K. French, Environmental Planner
DATE:June 12, 2013
SUBJECT:Update onSlacklining, Highlining, Ziplining, and TyroleanTraverses
________________________________________________________________________
Background
Severalyears ago, thequestion of highlining and ziplining(see Attachment A for definitions of
the various activities referred to in this memo) on Open Space and Mountain Parks (OSMP)
landsarose.Staff consulted with the Office ofthe City Attorney(CAO). The CAO opinionwas
that highlines, ziplines, and slacklinesconstituted structuresand were not permissible per the
Boulder Revised Code(B.R.C.)8-3-21Tents and Nets Prohibited.“No person shall erect any
tent, net or structure…on any open space land, unless done pursuant to a written permit or
contract from the city manager.”
An additional ordinance, B.R.C.6-6-6 (c)Protection of Trees and Plants,also applied to
Slacklining:“No person shall attach to or install on any tree or plant growing within or upon
any City-owned or controlled property…without first having obtained approval from the city
manager…”Although this ordinance contains language allowing for the establishment of arule
or permit system to grant permission to attach to trees, no such rule or permit system hasbeen
established.
In 2012 a ziplining incident occurred on OSMPpropertyand a summons,citing a violation of
8-3-21,wasissued.The incident went to trial, the application of 8-3-21 was questioned, and the
citation was not upheld. The CAO consequently recommended that staff create a more specific
regulationprohibiting zipliningif the activity was thought to be contrary to established policy.
Staff drafted an emergency rulewhich was published in the Boulder Camera in the beginning of
December2012with a 30-day public comment period.
Rule Prohibiting affixing ropes, cables, or webbing horizontally between anchor points on
OSMP properties.
No person shall affix or use any rope, cable, webbing or similar material affixed to two or more
anchor points for the purpose of traversing horizontally on any Open Space and Mountain Parks
property. This rule prohibits structures commonly called “Slack Lines,” “Tightropes", “Zip
lines”, “High Lines” or “TyroleanTraverses.” It is sufficient to violate this rule if a person
affixes any rope, cable, webbing or similar material to one of the potential anchor points. It
shall be an affirmative defense to any action to enforce this rule that the defendant was engaged
in otherwise permissible rock climbing, rappelling or other activities involving vertical climbing
Agenda Item 3B Page 1
or acted with the authorization of the City Manager for public land management, wildlife
management, search and rescue, or public safety purposes.
At the Dec. 12, 2012 Open Space Board of Trustees (OSBT) meeting a Board member raised
concernsabout the inclusionof Tyroleantraverses and slackliningin the draft rule. The Board
member noted there areTyroleantraverses in Boulder Canyon,althoughit was unclear whether
any wereon OSMP property. Staff was encouraged to expand thepublic process, allowing for
moreinputfrom the user groups. The Board also expressed an interest in examining the
activities to determine whether they would be considered passive recreation and where/if some
of the activities could be allowed. Staff clarified that the existing Protection of Trees and Plants
ordinance prohibitedattaching anything to a city-owned tree. Staff stated further investigation
was necessary to determine if any of the Tyroleantraverses in Boulder Canyon were on OSMP
propertyand committed to follow up with the Board.
During the initial follow upon the OSBT’s Dec.12 direction,staff determined that activity
assessmentshad not been completedfor the subject activities. Staff does notconduct activity
assessments for activities considered to be illegal under an existingcity ordinance—as the
subject activities previously were interpreted to be. Activity assessments are identified in the
City Council approved Visitor Master Plan (VMP)as the process to determine 1) whether or not
“new” recreational activities are passive andappropriate on OSMP property and 2) determine
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necessary conditions or infrastructure to avoid or minimize impact.
However, with the change in interpretation of 8-3-21Tents and Nets Prohibitedthe need to
evaluate the activities arose. Staff communicated to the Boarda shared desire tocomplete
activity assessments and provide an opportunity for public input.
Activity Assessment Status
Staff completed step oneof theactivity assessmentsfor highlining, ziplining and slacklining,and
initially determined that slacklining and highlining were passive andmay be appropriate in some
areas with conditions. Whencompleting step two of the activity assessments,developing
recommendations about the appropriate areas/necessary conditions to minimize impacts,a
broader and unresolved management issue emerged.The issue is how to constrain off-trail
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activities on OSMP outside of Habitat Conservation Areas (HCAs).
Staff was considering limiting slacklining to Passive Recreation areas.In order to allow
slacklining in Passive Recreation areas, staff could either develop a “City Manager’s Rule” or
create an ordinance specifyingthe location where the activitieswould be allowed.City
Manager’s Rules are preferred due to their flexibility and are the regulatory authority most often
used to regulate activities on OSMP;ordinances are more inflexible andtypically used for
outright prohibition.However, the ordinance enabling the City Manager to issue rules
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Activity assessments include a consideration of four factors: 1) compatibility with other recreational activities 2)
compatibility with resource protection 3) compatibility with existing facilities and services, and 4) the activities’
relationship to the natural setting.
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The city is able to prohibit certain activities (e.g. off-trail travel) in HCAs because the HCA boundaries have been
signed.
Agenda Item 3B Page 2
B.R.C.8-3-3(c), appears to require the city to sign boundaries or create a permit system to limit
off-trail activities to specific areas(ordinances also requirethe city to sign the boundaries).
8-3-3(c) The manager shall post rules issued under this section at the place where they are to be
enforced. If the rule is not posted, it may still be enforced if the person had actual knowledge of
the rule, was given a copy of the rule upon applying for or receiving a permit or a license, was
advised of the rule by a city employee, or was ordered by a peace officer to cease conduct
violative of the rule.
The past and current interpretation of8-3-3(c) requiring thecity to sign the boundariesor create
a permit system greatly reduce the feasibility of allowing slacklining in Passive Recreation areas
bymakingitfar more expensive and impractical.However, in conversations with the CAO, it
was suggested there may be room for interpretation, and signing the entire Passive Recreation
boundary may not be necessary. The CAO staff also explained that it was a complex issue that
would require extensive research and allocation of time to resolve.
Given the current lack of clarityand room for interpretationregarding 8-3-3(c)staff was unable
to completethe activityassessments.Staff thought itpremature to conclude that there isno
feasible wayto prohibitoff-trail activitiesin specific areasother than HCAsand has put the
activity assessments “on hold.”
Current Status
Slacklining will continue to be prohibited,per6-6-6 (c)Protection of Trees and Plants.
Tyroleantraversesattached to treeswould also be prohibited.However, staff isworking with a
surveyor to determine if the Tyroleantraverse west of Boulder Falls is on OSMP property. This
traverse is very close tothe estimated property boundary andthe existing information about the
location of the property boundary is inconclusive when trying to make a determination.
There is no specific rule or ordinance prohibiting highlining and ziplining. OSMP has the
authority to regulate these activities if they occur and are damaging naturalresourcesor
endangeringpublic safety.
Next Steps
OSMP staff will workwith the CAOto explore options surrounding the requirements of
8-3-3(c). More clarityabout the requirements willhelp staff complete assessmentsfor off-trail
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activities, implement the West Trail Study Area (TSA) Plan,and develop upcoming TSAplans.
Once there is greater clarity about the range of options, staff will complete the activity
assessments for slacklining, highliningand ziplining.
Staff will continue to work withasurveyorto determine if the Tyroleantraverse west of Boulder
Falls is on OSMP. If it is determined that the traverse is on OSMP property, staff is considering
establishing a permit system similar to the fixed hardware permit system to facilitate safer access
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The City Council and OSBT approved off-trail horseback riding recommendations in the West TSA limit off-trail
riding toa subset of area (generally west of the Mesa Trail) outside of HCAs.
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to climbing routes. If successful,this approach would identify a party willing to take
responsibility for the Tyrolean traverse and its maintenance.
ATTACHMENT
A: Activity Descriptions
Agenda Item 3B Page 4
Attachment A: Activity Descriptions
Slacklining
Slacklining is a balance sport or activity practiced for athletic benefit, meditative purposes,
and/or just for the pleasure of the experience itself. Slacklining typically involves the use of
webbing (a strong fabric often woven as a flat strip) fixed horizontally and tensioned between
two anchor points, the most common anchors being trees. Participants attempt to walk across the
webbing and/or perform various feats. Slacklining is distinct from tightrope walking in that the
line is not rigidly taut, it is instead dynamic, stretching and bouncing when participants are on the
line. Slacklines are typically close enough to the ground that participants can easily step on and
off, and no protective harnesses or ropes are used.
Highlining
Highlining differs from slacklining in that the line is elevated and the anchors typically are
constructed using bolts or traditional (removable) climbing gear inserted into rock formations.
Most participants wear a climbing harness with a leash attached to the highline to ensure safety
in the event of a fall.
Ziplining
Ziplining is an activity where participants, propelled by gravity, travel from a higher elevation to
a lower elevation along an inclined rope or cable, typically with the intent of rapid acceleration.
Ziplines vary in length, heightand angle of descent.
Tyrolean traverses
A Tyrolean traverse is a method of crossing through free space between to elevated points. This
is used in a range of mountaineering activities including rock climbing and water crossings. A
Tyrolean traverse typically involves the use of rope fixed horizontally between two anchor
points. Participants, using harnessesand a specialized pulley or other climbing gear, attach to
the rope and pull themselves across.
Agenda Item 3B Page 5