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Carolyn Holmberg Preserve at Rock Creek Farm Management Plan Update

Carolyn Holmberg Preserve at Rock Creek Farm Management Plan Update

An amendment to the management plan is being considered to establish a trail connection from the Stearns Lake Trailhead northward to the northern property boundary at 104th Street and Dillon Road.


Boulder County Parks & Open Space (BCPOS) is working in partnership with the cities of Lafayette and Louisville to create a 2.9-mile connector trail along S. 104th Street from the Rock Creek Trail and Stearns Lake Trailhead at Carolyn Holmberg Preserve at Rock Creek Farm (CHP/RCF) to the Coal Creek Trail. An amendment to the CHP/RCF Management Plan is necessary to establish a formal trail connection for a 0.6 mile portion of this regional trail connector from the Stearns Lake Trailhead northward to the northern property boundary at 104th Street and Dillon Road. If approved by the Board of County Commissioners, this amendment will formally become part of the Carolyn Holmberg Preserve at Rock Creek Farm Management Plan.

Public Hearing

A public hearing will be held on Oct. 8 with the Board of County Commissioners. Public comments will be accepted.

Tuesday, Oct. 8, at 9 a.m.
Boulder County Courthouse – Commissioners’ Hearing Room
1325 Pearl Street, Boulder

Proposed trail at CHP


CHP/RCF was purchased by BCPOS starting in 1980. It is a multi-faceted property used for agriculture, recreation, and protection of native plant and animal habitat.

The requested amendment would allow for a trail along the east side of 104th Street from the Stearns Lake Trailhead to the CHP/RCF northern property boundary at Dillon Road. The trail would then continue north to complete a connection to the Coal Creek Trail utilizing the 104th Street roadway right of way and/or open space properties identified in the Jointly Owned Boulder County-Lafayette-Louisville Open Space Management Plan adopted in 2004 by the City of Louisville, City of Lafayette, and Boulder County.

While reviewing the need for this plan amendment, the department considered performing a full update of the entire CHP/RCF Management Plan since there are several resource and management issues in the full property that also need resolution. However, it is anticipated that a nine- to 12-month planning process would be needed to allow for plan development. The proposed amendment to include a conceptual trail alignment for the 104th Street Connector Trail is being requested now because the impacts to open space resources are anticipated to be minimal, and the City of Louisville in partnership with Lafayette and Boulder County was awarded grant funding in August to design and construct the 104th Street Connector Trail. This small, trail-corridor-only plan amendment can be completed quickly to keep the trail project on schedule and the larger update to the CHP/RCF will commence later this fall and last into next year.

A site visit in early July by BCPOS staff representing disciplines from Agriculture, Recreation and Facilities, Resource Management, and Resource Planning did not identify major concerns with the connection.

Input from staff is included:

  • The Glacier View parcel encompasses the NW portion of CHP/RCF bordering Dillon Road and S. 104th It is agricultural cropland that is irrigated with a center pivot. An existing recycled asphalt, surface farm access road parallels S. 104th Street. It is envisioned that the trail could be located between the farm access road and S. 104th Street roadway.
  • The proposed trail alignment would use the public right-of-way adjacent to a private parcel along the east side of S. 104th However, potential acquisition of an easement or land may be needed if right-of-way width is limited.
  • While S. 104th Street is a dirt road south of Dillon Road, a short stretch at the low point in the topography was improved to a concrete surface due to potential stormflows/drainage overtopping the roadway. The proposed trail design may also need to accommodate drainage in this area.
  • The proposed trail alignment would cross a freshwater emergent wetland associated with the inlet to Stearns Lake and adjacent Goodhue irrigation ditch lateral. Impacts to the wetland area can be minimized by installing a bridge/boardwalk over the feature approximately 170 feet in length from start to end that spans both the wetland and ditch. The trail should attempt to cross this feature most directly for the smallest wetland impact (and smallest cost, should a bridge or boardwalk be required). Construction of the bridge/boardwalk over this habitat should be timed to avoid the nesting season (April 15 through Aug. 1). Depending on the design of the bridge/boardwalk, there could be some minor impacts to the wetland during construction. Any disturbance, however, with the exception of any posts and pilings, would be temporary in nature, and all standard conservation and erosion control measures would be adhered to during construction.
  • Staff did not observe any recently active raptor nests or burrowing owls along the route. However, the route will be monitored and mitigation identified as appropriate if needed before construction.

Regional Trail Context

The Boulder County Comprehensive Plan states that the county will work with the Consortium of Cities to assure linkages of county trails and connections between communities. This connector trail would provide a link between two popular regional trails and allow residents of Lafayette, Louisville, and Broomfield to access CHP/RCF and its trail system.

The City of Louisville submitted a grant application for the design and construction of the connector trail, which would fund 50% of the $950,000 estimated project cost. The City of Louisville, City of Lafayette, and Boulder County would each contribute $158,333.33, which would fund the local match balance of the total project cost.

Public Process

Property owners within 1,500 feet of proposed 104th Street Connector Trail on the impacted open space parcels at CHP/RCF received a letter by direct mail in advance of both this BOCC hearing and a July POSAC meeting. BCPOS staff shared information about the proposed management plan amendment and provided details regarding the respective public meeting date, time and location, and opportunity to attend and provide verbal testimony.

On July 18, BCPOS staff representatives met on-site with an adjacent private property owner to discuss the potential trail alignment. The property owner expressed support for a trail along the east side of S. 104th Street, in front of their property and a willingness to work with the county should potential acquisition of an easement or land be needed if right-of-way width adjacent to their property is limited.

POSAC Recommendation

The staff recommendation was brought to the Parks & Open Space Advisory Committee (POSAC) on Thursday, July 25. Links to the meeting materials presented, as well as video and minutes are available on the POSAC Open Meeting Portal.

During the public comment period of the meeting, two community members spoke on behalf of Groundwork Ranch, a non-profit organization located on the NE corner of S. 104th Street and Dillon Road. Groundwood Ranch provides equine-assisted learning programs. Both speakers expressed support for the trail, yet also shared concern for the proximity of the trail to their horse-riding facility citing trail user, client, and horse safety as well as privacy as issues. They offered suggestions for incorporating privacy screening such as a mature hedge, fencing, or trees. They would like to be kept updated on the trail and also suggested a site visit to discuss in person. BCPOS staff advised POSAC that this property is located within Louisville, and that the comments would be shared with the project team and that BCPOS staff anticipates that Louisville will work with the ranch since it is within their jurisdiction.

After a staff presentation, POSAC unanimously made a recommendation that the BOCC support the staff recommendation to amend the Carolyn Holmberg Preserve at Rock Creek Farm Management Plan to include a conceptual alignment for the 104th Street Connector Trail along the east side of the roadway.

Staff Recommendation

Staff recommends the BOCC approve this amendment to the Carolyn Holmberg Preserve at Rock Creek Farm Management Plan to establish a formal trail connection from the Stearns Lake Trailhead/Rock Creek Trail northward to the northern property boundary at 104th Street and Dillon Road.

Next Steps

Upon approval of this amendment, BCPOS will enter into an IGA with the City of Louisville and City of Lafayette to provide specific conditions related to the trail connection such as responsibility for trail design, construction, routine and capital maintenance, and the designation of trail use rules, regulations, and enforcement.

The City of Louisville will be the fiscal agent for the state-funded grant project. Funding will be received in October 2019. Design of the trail would begin in late 2019 and the trail would be constructed in 2022. As part of the initial steps of the design process, the project agency partners will schedule public forums to get input from community stakeholders.

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