Natural Rescource Management Plan
Planning for a Sustainable Long-Term Future for the Canal
Background
The High Line Canal is a resource in transition, as Denver Water reduces its reliance on the Canal for irrigation delivery and local jurisdictions formalize the use of the Canal for stormwater management. This change in water availability is already impacting the Canal's natural resources, as water-loving trees are challenged with less water in the Canal and many of these trees reach the end of their natural lifespan. The Canal is a quasi-riparian system, while it has mimicked a natural waterway over the course of 140 years of irrigation delivery the Canal is not a river or stream. These irrigation flows gave life to a novel ecosystem, or ecosystem significantly altered by humans, and while stormwater may be able to support this riparian character in some areas of the Canal, other reaches of the corridor will naturally transition back to a native, prairie ecosystem.
Natural Resource Management Plan
In 2024, the Canal Collaborative partners came together and pooled funding to develop the Canal’s first Natural Resource Management Plan (NRM Plan). The NRM Plan describes the Canal’s existing conditions, defines new maintenance and management practices, and prioritizes restoration and enhancement opportunities. While the presence of stormwater will continue to support riparian character in some areas of the Canal, other areas are already transitioning back to a native prairie ecosystem that predates the Canal. The NRM Plan will support the transition of maintenance and management responsibilities on the Canal and support restoration and enhancement efforts, such as tree planting and watering.
Maintenance and Enhancement Strategies
The graphic below summarizes the overarching maintenance and enhancement strategies that are recommended in the NRM Plan.
High Line Canal Prairie Ecosystem in Aurora
Enhancement Recommendations
- Irrigated or stormwater-supported tree planting can more quickly and successfully establish new trees
- Stormwater can support the establishment of native shrubs like Plum and Chokecherry that had been prevalent along the Canal
- Areas with limited stormwater availability where irrigation is not desired may revert back to a prairie landscape and can be enhanced with native grasses and forbs
Maintenance Recommendations
The maintenance recommendations described below represent the types of changes in how the Canal is managed that trail users can expect to see in the coming years:
- Management of the Canal for recreation and stormwater will require more proactive tree canopy care
- Invasive and undesirable understory is impacting the establishment of native and desirable vegetation and should be thinned
- Mowing beyond the trail shoulder or recovery zone is not needed and mowing on the Canal will be reduced
- Noxious weed management should be more targeted and should be integrated with restoration as feasible
- Additional maintenance may be needed in areas that convey stormwater compared to areas with little stormwater flow
High Line Canal Riparian Ecosystem in the City of Centennial
NRM Plan Implementation
The Conservancy is working actively with all of the Canal Collaborative partners to implement both maintenance and management improvements as well as restoration and enhancement opportunities. Maintenance and management approaches are evolving as local jurisdictions responsible for recreation and stormwater management assume responsibilities from Denver Water. Restoration and enhancement projects are also underway, as the Conservancy works with these local jurisdictions to plant and water trees and shrubs as well as native grasses and forbs. While it will take decades for the Canal’s landscape to evolve to a more sustainable plant community, the Conservancy will be leading this work alongside our partners across the Canal to ensure the corridor remains a natural refuge for generations to come.
Your support is critical to this effort. In the words of conservation pioneer Rachel Carson, “Conservation is a cause that has no end. There is no point at which we will say our work is finished.”
