Landscape Performance Benefits
- Sequesters nearly 31,200 lbs of carbon annually in the 44 mature globe willow trees and 18 Colorado blue spruce trees that were transplanted during construction.
- Creates ideal trout habitat conditions with dissolved oxygen levels at or greater than 7 ppm and water temperature at or less than 60°F, following the pond redesign. Trout could not be sustained previously.
- Reduces the project’s landfill burden by over 3,700 cu ft by donating material from the existing home to Habitat for Humanity. The recycling of the pine logs alone reduced the total amount of CO2 equivalent produced by approximately 22 tons.
- Reduces irrigation and fertilizer needs by nearly 60% by replacing 5,020 sf of turf with native plants. This saves over 75,000 gallons of water and eliminates the need for 30 lbs of fertilizer annually.
- Blocks approximately 97.8% of unwanted views with earth berming, plantings, and retention of mature trees to reduce visibility of traffic on the nearby road from key points on the property.
At a Glance
Design Workshop, Inc.
Former Land Use
Cascade Garden is a tranquil, high-altitude residential property, designed to preserve the area’s natural setting and ecosystem while meeting the propery owner’s requests for outdoor amenities. The project involved dismantling an existing house and siting a new home integrated into the landscape with minimal site disturbance. The site features an existing pond, which was planted with riparian vegetation and modified to support trout habitat and supply water for landscape irrigation. Because of the harsh, high-altitude climate and presence of wildlife, plant species were carefully selected to ensure high growth levels and low maintenance. Most of the traditional lawn was replaced with native plants, which conserve water and reduce fertilizer consumption. The home also employs renewable energy through a ground-source heat pump that is used to operate outdoor site features. The design creates a serene environment that complements its surroundings and provides the relaxing outdoor spaces the homeowners sought.
- The landscape surrounding the home features a healthy aquatic ecosystem complete with a pond and cascading creek, preserved native flora, and outdoor spaces designed to complement their natural surroundings.
- The existing pond was reshaped while maintaining its surface area of 0.84 acres, deepened to more than 12 ft, and planted with riparian vegetation to improve water quality and provide habitat for trout and other aquatic life.
- The three-tiered patio is constructed of native stone and provides about 600 sf of outdoor space overlooking the pond.
- Based on the recommendations of the landscape architect, the new home was located on the footprint of the previous house to minimize site disturbance. The steep slopes directly north of the home site were not impacted during construction and approximately 18,000 sf of native vegetation on the slopes was retained and enhanced with additional plantings.
- Over 2,500 sf of the access drive was located on previously disturbed ground, minimizing construction impact.
- Grading and water features capture and infiltrate or utilize all stormwater that falls on the site, eliminating the need for a connection to the municipal storm sewer system. Non-potable water collected on-site is used for all landscape irrigation.
- A ground-source heat pump reduces energy demand from off-site, replacing carbon-based electricity with a renewable source.
Hurdles faced during the design of Cascade Garden stemmed largely from the juxtaposition of client requests and environmental limitations. Preservation of the central pond along with the creation of viable habitat for wetland vegetation were top ecological priorities that had to be reconciled with fishing and boating requests. The existing house on the site required responsible disposal to make way for a chief client preference: a newly constructed residence that nonetheless maintains the appearance of history and permanence of the property. Stormwater and snowmelt needed to be contained on-site and used in place of traditional irrigation techniques. Above all, designing for visual aesthetics within a limited native plant palette and developing the natural beauty of the location were top priorities.
The success of the Cascade Garden project revolved around meeting traditional residential client needs using non-traditional approaches. The existing pond was deepened and planted with native wetland species to create trout habitat and meet recreational needs while maintaining pre-design water surface area. Although the existing home was dismantled, new construction was sited over the footprint of the previous building to avoid additional site disturbance, and materials and appliances were donated to local charities. The landscape plan retained mature trees across the property to lend a sense of permanence and character, while also preserving the steep slopes adjacent to the home site. Wildlife such as ducks, deer and bear, still frequently visit the site. Finally, swales collect all stormwater and snowmelt, which is repurposed for landscape irrigation.
- By installing a ground source heat pump to provide renewable energy, the design avoided approximately $97,000 dollars in current Pitkin County Renewal Energy Mitigation Program fees. Purchase and installation of the unit totaled $83,000. Annual maintenance of the pump costs $1,500 annually when averaged over the five years since installation, which is competitive with maintenance costs of traditional commercial units.
- The original planting plan for the perennial garden evolved over time as client preferences changed and limitations imposed by climate and altitude at the site became better understood. Since the installation, the landscape architect has repeatedly added new plants that are more adaptable to the unforgiving setting. The homeowners are actively engaged in this process, working with the landscape architect to identify plants that can withstand the harsh planting zone while still providing the desired visual impact. The garden serves as a reminder that great landscapes develop over a long time and with a lot of effort, both on the part of the designer, but also through devoted maintenance and client input. Educational and therapeutic opportunities were discovered through the integration of the client input into the garden design.
Master Plan & Landscape Plan: Design Workshop, Inc.
Aquatic/Pond Consultants: Aqua Sierra, Inc.
Architect: Shope Reno Wharton Architecture
General Contractor: Hansen Construction
Landscape Contractor: Landscape Workshop
Role of the Landscape Architect
The landscape architect sited the home on the property and designed all elements exterior to the home itself including hardscape patios, gardens, pond, retaining walls, access drives, and plantings.
Case Study Prepared By
Research Fellow: Bo Yang, PhD, Assistant Professor, Utah State University
Research Assistant: Pamela Blackmore, BLA, Utah State University
Research Assistant: Chris Binder, MLA Candidate, Utah State University
Firm Liaisons: Allyson Mendenhall, Ashley Allis, and Kurt Culbertson, Design Workshop
Yang, Bo, Chris Binder, and Pamela Blackmore. “Cascade Garden.” Landscape Performance Series. Landscape Architecture Foundation, 2013. https://doi.org/10.31353/cs0650