Silt Preserve on the Colorado River

The 132-acre Silt River Preserve is now owned by the Town of Silt and conserved through the Aspen Valley Land Trust (AVLT). Once heavily grazed and later identified as part of a proposed 2,000‐unit development along 0.6 miles of the Colorado River, this land is relatively degraded, but with excellent restoration potential to become a natural, riverside park. The expansive extent and limited development of the preserve allow for numerous restoration opportunities to re-establish a high-quality riparian and transitional upland interface ecological community. Additionally, the variety of habitat types and diversity of wildlife in the preserve present unique opportunities to conduct restoration with specific species and habitat interventions.

There is an opportunity to create a functional wetland community in the northwest quadrant of the preserve. The extent of the wetland habitat creation is dependent on the desire and resources available for the efforts and a better understanding of the natural hydrology and depth groundwater. The location and method of diverting water from the ditch is being assessed. Three freshwater ponds consisting of 3.01 acres have been identified for possible wetland habitat enhancement. Currently, these ponds provide excellent nesting, foraging habitat and cover for a diversity of birds, small mammals, reptiles and amphibians. Given the current trend of hydrological conditions in the west, these freshwater ponds are likely more consistent with an emergent wetland classification. The vegetative diversity within these habitats is low, consisting of high densities of cattails and soft-stem bullrush.

Enhancement of freshwater pond habitats through active measures would allow the ponds to resemble a more open freshwater pond habitat with peripheral emergent wetland along the ponds edges. To proceed with this, a portion of the current decreed water rights could be converted from agricultural to piscatorial or storage use. This water could then be utilized to maintain more regulated inundation of water in the pond system and manage the water regime to maintain the pond capacity.

The established emergent vegetation that dominates the pond basins should be removed and maintained in a way that is beneficial to the system moving forward. The enhancement of the freshwater ponds will provide improved aquatic and water fowl habitat to the site.

On behalf of Middle Colorado Watershed Council (MCWC) , Wright Water Engineers, Inc. (WWE) has completed several key tasks regarding the water rights for the Silt River Preserve. Through multiple site visits to the property, WWE developed an understanding of the existing conditions for the irrigation ditches and laterals, onsite ponds and related infrastructure, and observations of current and potentially irrigable lands on the property. 

WWE reviewed the Water Court decrees in Case No. 98CW131 associated with the Stillwater Ranch, a larger project that contained the Silt River Preserve, to assess how the water rights and plan for augmentation could be utilized for the existing and proposed development of the onsite ponds.  Working closely with the Town of Silt’s water attorney who own the property and the water rights, WWE evaluated what changes might need to be made to the existing decree to accommodate the proposed project.  Mapping shows the decreed historically irrigated lands combined with the Town of Silt’s irrigation improvement plan and the conceptual plan for the site developed for Aspen Valley Land Trust.

 WWE prepared an engineering technical memorandum outlining the water rights implications and options for three development phases. The initial phase that was funded in 2022 worked with the existing conditions of the three onsite ponds. With additional funding, the second phase could enhance the ponds and associated infrastructure, and the final phase is the lining of one pond for continuous storage to provide for multi-purpose uses.  Included in the engineering analyses are dry up requirements and contract storage water needs for each phase of the project. 

RE: Silt River Preserve Volunteer Planting and Restoration

Funding from the Colorado Water Conservation Board in 2022 also allowed for invasive species removal and revegetation around the eastern most pond, Pond 8.

On Oct. 15, 2022, revegetation efforts around Pond 8 at the Silt River Preserve were completed as a collaborative effort between the Middle Colorado Watershed Council, the Town of Silt, Aspen Valley Land Trust, Roaring Fork Outdoor Volunteers and DHM Design. More than 30 volunteers showed up to plant 415 native tree and shrub species adapted to Colorado River floodplain ecology. The fringes of the pond and transitional and upland areas adjacent to the pond were fully revegetated through this effort, with approximately 1-acre being seeded utilizing native site specific seed mixes developed for restoration efforts at Silt Preserve.

For this effort, restoration activities were focused around a large depression in the transitional area located between the eastern pasture and the riparian shrublands of the Colorado River. The intent of this focused restoration is to revitalize the hydrology, creating a wetland habitat pond and establish native shrub and tree species, providing vital wildlife habitat for forage and cover. To initiate the restoration, invasive Siberian elm (Ulmus pumila), Russian olive (Elaeagnus angustifolia) and salt cedars (Tamarix ramosissima) have been removed and approximately 10,000 sq. ft. around the existing depression have been excavated and graded to better support the functionality of the wetland habitat pond. The additional benefit of the grading was to prepare the site for the plantings and provide planting locations better connected to the ground water and hydrology of the pond.

Referencing native vegetation found throughout the intact riparian communities of Silt preserve, native shrub and tree species were acquired for the volunteer planting. These species include: narrowleaf cottonwood (Populus angustifolia), plains cottonwood (Populus deltoides), redtwig dogwood (Cornus sericea), twinberry (Lonicera involuctra), threeleaf sumac (Rhus trilobata), Rocky Mountain willow (Salix monticola), and silverbuffalo berry (Sheperdia argentea).

Overview of restoration activities completed on October 15th, 2022:

*415 native shrubs and trees planted

*All trees mulched with 6” around the drip line of the tree

*Approcimately one acre of upland and transitional area were seeded with native riparian seed mix

*Seeded area was covered with straw

*8 ft tall wildlife fencing installed around planting area to protect from deer and elk browse