A Collaborative Approach to Riparian Restoration
by Celestine Duncan, Photos by Mark Taber
Flowing north from its headwaters in the San Juan Mountains of western Colorado, the Dolores River meanders through iconic canyons and broad valleys as it descends to its confluence with the Colorado River more than 200 miles downstream. Like many rivers that have been dammed in the West, a combination of altered flows and introduction of invasive plants such as tamarisk (Tamarix spp.) has reduced biodiversity and impacted the health of the Dolores River.
In 2009 a coalition of private landowners, communities, nonprofit organizations and government agencies (Box 1) took action to restore about 175 miles of riparian habitat along the Dolores River between McPhee Reservoir and its confluence with the Colorado River just north of Moab, Utah. Mark ‘Sparky’ Taber, natural resource specialist for the Bureau of Land Management in Grand Junction, Colorado, is a key player in the partnership. “Our goal is to erase boundaries and implement the restoration work where it’s needed, regardless of whether it’s public or private lands,” explains Taber.
Trust is a large part of making the public-private partnership work. “Building relationships and following through with a plan of work is critical, especially if you want private landowners to come on board. They have to see results to know that the project is effective and that other partners are committed,” says Taber. “What is so great about being part of this project is that we develop plans through consensus that include both public and private lands. This helps secure funding and provides a network of individuals that can help with project direction, oversight and long-term maintenance.”
The first large scale project on the river started just below McPhee dam in the fall of 2010. Since that time, the partnership delineated 94 work units that span the entire length of the river, and designed management prescriptions for each unit. Restoration on many of those work units is complete or in the process of being completed (Box 2 and Figure 1).
Management includes integrating biological control agents with manual and mechanical removal of tamarisk, herbicide treatment of tamarisk regrowth and herbaceous weeds such as Russian knapweed, and restoring desirable native riparian species. Site conditions, tamarisk density, presence of other native or non-native vegetation, and physical access determine what method is prescribed on each of the work units.
“The Conservation Corp crews are a key part of our success,” explains Taber. “Crews are employed to cut tamarisk or other woody invasive trees in areas where the trees are scattered, or where access for machinery is difficult (Figure 2). In areas with dense tamarisk and very little desirable understory, excavators with a grapple are used to pull and stockpile trees which are burned after drying (Figure 3). This method leaves less woody debris on the ground, minimizes opportunity for regrowth, and is faster than mulching an entire tree (Figure 4). It’s an aggressive approach, but you can selectively remove invasive woody plants from desirable native plants such as New Mexico privet (Forestiera neomexicana), which helps restoration efforts,” says Taber.
Tamarisk leaf beetles (Diorhabda sp.) have been present on the Dolores River since 2005, and have weakened or killed tamarisk in some areas (Figure 5). Combining mechanical treatments in areas where beetle density is high reduces the amount of regrowth following cutting. Tamarisk that does regrow is treated with Garlon® 4 Ultra herbicide in oil applied as a basal bark treatment in late fall and winter (Figure 6).
Mechanical removal of tamarisk and other invasive woody plants is conducted during the fall and early winter. Herbaceous weeds such as Russian knapweed are treated the following summer or fall. “On BLM lands we were using Transline® herbicide on Russian knapweed, but we just received approval to use Milestone® herbicide so we will be applying that on Russian knapweed in 2017,” explains Taber.
The gall nematode (Subanguina picridis) is also established on some Russian knapweed infestations in the project area resulting in stunted plants. Once invasive plants are removed or reduced in abundance, the site is restored by seeding desirable vegetation and/or planting cottonwood and willows.
The Dolores River Partnership has completed more than 70 percent of prioritized restoration along 175 miles river. The commitment and energy leveraged through the partnership has allowed for landscape-scale restoration with financial, technical, and human resources shared across jurisdictional boundaries. The partnership also created an effective career path in natural resource management for young adults that are part of the Conservation Corps.
“The scope of the project and acres of riparian habitat restored on the Dolores River could never have been done without the benefit of the Partnership,” says Taber. “Our collective efforts have knocked back tamarisk and other invasive plants for a long time, maybe decades—but without continued monitoring and maintenance these plants can reinvade. It is so critical that we continue to build on existing relationships, and establish long-term funding levels so we can protect what we’ve accomplished. Meeting this goal is likely our biggest challenge for the future.”
Box 1. Dolores River Restoration Partnership: Participating Agencies in Cooperation with Private Landowners
Bureau of Land Management (Dolores, Montrose, Grand Junction & Moab Offices)
State of Colorado
Colorado Division of Parks and Wildlife
Colorado counties of Dolores, Montrose, San Miguel, Mesa & Grand (in Utah)
The Nature Conservancy
Walton Family Foundation
Rocky Mountain Bird Observatory
Southwest Conservation Corps
Canyon Country Youth Corps
Western Colorado Conservation Corps
Natural Resources Conservation Service and Conservation Districts
Colorado Division of Wildlife
Utah Division of Wildlife Resources
Colorado Department of Highways
Unaweep Tabeguache Scenic Byway
Department of Energy
Partners for Fish and Wildlife -Colorado and Uta
Box 2. Dolores River Partnership: Restoration by the Numbers (2009-2015)
1,430 acres of tamarisk removed
3,615 acres of tamarisk re-sprouts and secondary (herbaceous) weeds treated
497 acres of re-vegetation
15 structures and facilities where fuel loads were reduced
27 miles of scenic vistas and sight lines improved along Highway 141 (Scenic Byway)
23 riverside campsites improved for recreationists
JOBS CREATED AND HOURS OF SERVICE
41 jobs created for local contractors
276 jobs for youth and young adults through Conservation Corps
95,380 hours of work contributed by Corps crews, interns, and strike teams
130 hours (on average) of training for each Corps member
$6,586,453-- expenditures and in-kind resources invested in the region's economy
For more information on the Dolores River Partnership
A collaborative model for large-scale riparian restoration in the western United States Oppenheimer JD, SK Beaugh, JA Knudson, P Mueller, N Grant-Hoffman, A Clements, and M Wight. 2014. Restoration Ecology
Leaving a legacy on southwest rivers
Mike Wight. 2015. River Management Society Journal
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Active ingredients for herbicide products mentioned in this article: Milestone (aminopyralid), Transline (clopyralid), Garlon 4 Ultra (triclopyr).