DAY∙LIGHT∙ING (verb) - the act of uncovering an underground waterway by bringing it to the surface and, typically, restoring to a natural state.
As Emigration Creek runs west, its waters slip into an underground pipe just outside Westminster College’s campus, at Wilson Avenue. The creek was dubbed a nuisance by decades of city planners during 20th Century urbanization of the valley. According to research by the Seven Canyons Trust, approximately five miles of Emigration Creek are buried. Additionally, five miles of its aboveground channel are impaired under the Clean Water Act’s 303(d) List of Impaired Waters, according to Salt Lake County’s 2015 Integrated Watershed Plan. Loss of green space and water quality impairments, due in large part to creek burial, have left many without access to nature or connectivity.
Water quality issues persist because of inadequate management. The piping and channelization of creek channels has sped up water velocities, increasing erosion and sedimentation. Urban runoff, high in nutrients, has caused harmful algal blooms in downstream affected communities, a public health risk for children and pets, a detractor of recreation and agriculture, and an ecological disaster for wildlife. Culverting transports nutrients eight times further downstream (Effects of urban stream burial on nitrogen uptake 247). Revitalizing creeks will address water quality impairments, flooding, economic vulnerabilities, and quality of life, in the larger rehabilitation of Salt Lake City.
The Emigration Creek culvert, from Wilson Avenue to Liberty Park, experiences frequent seasonal flooding, especially at the Wilson Avenue headgate. Salt Lake County recently updated the input. However, work is but a band-aid solution for easing pressure on the stormdrain. The culvert is undersized through this section and can become highly-pressurized in high creek stages. Most notably, blowing-off manhole covers in the 1983 floods.
Case of Support
From Zürich, Switzerland to Hutchinson, Kansas, communities across the globe are transforming antiquated stormwater systems with green infrastructure to benefit resiliency, environmental integrity, and quality of life. The benefits of daylighting are far-reaching. New channels create a nexus between surface water, or creek water, and the ground to facilitate recharge. Groundwater is an increasingly important source of drinking water for Salt Lake County with climate change uncertainty and a growing population.
Creeks slow down water velocities, when compared to smooth concrete pipes, through meanders and woody, rough banks. Stormwater culverts create choke points and can pressurize during precipitation events. Evidence from floods in 1983 suggests culverts became obstructed with flood debris, rocks, even entire trees, coming from the canyons. This resulted in back flooding, which eventually spilled onto the streets. Although residents took advantage of this time to canoe and fishing on State Street, the event costed Salt Lake County approximately $34 million. In July 2017, a 200-year precipitation event expanded the capacity of the conveyance system. The flooding was disastrous in the Ballpark neighborhood of Salt Lake City, primarily around 1300 South. A major culvert runs down this street, conveying stormwater, as well as Red Butte, Emigration, and Parley’s Creeks to the Jordan River. The culvert was unable to handle the stormwater input, along with the already present creek water, resulting in property damage and delays.
Emigration Creek and the downstream Jordan River fall on the Environmental Protection Agency’s 303(d) List of Impaired Waters. Water quality impairments include nutrient loading, low dissolved-oxygen, temperature, and total suspended solids. Nutrients attach to sediment. As sediments are deposited, vegetation soak in nutrients. Contained in culverts, waterways lack the ability to deposit sediment and sustain plant communities. By daylighting, harmful algal blooms can be lessened in downstream, underserved communities along the Jordan by retaining nutrients at the source.
The Salt Lake valley’s hydrology is a critical stopping point for neo-tropical migratory birds on the Central Flyway, connecting South America to Canada. Riparian vegetation supports the nesting and breeding of these world-travelers. Additionally, an estimated 80 percent of Utah’s species rely on riparian areas. However, these habitats represent a meager 1.2 percent of the City’s total land area (Salt Lake City Riparian Corridor Study 14). New creek channels can enhance habitat value and support more biodiversity for Utah’s fauna. Moreover, the urban tree canopy and presence of water can cool surrounding air temperatures and reduce the urban heat island effect drastically; an oasis in the intense heat of Utah’s summers.
Beautiful creeks can improve economic conditions of neighborhoods. A University of North Carolina study found that properties adjacent to habitat restoration sites increased, on average, by $3,100 (The land value impacts of wetland restoration 3). When turning surface parking into a flowing creek, it is easy to imagine this number could become much higher.
Developers can improve bottom lines. Potential tenants would likely see the creek as a delightful amenity. Nature-starved urban residents and children will have newly restored access to nature. Much research has shown that nature is critical to the development of children and the mental and physical health of adults. The creek will become a place to relax or read a book. A place to celebrate. Additionally, daylighting efforts can facilitate surrounding development to create livable, walkable neighborhoods that improve quality of life.
Numerous Salt Lake City plans have envisioned daylighting, dating all the way back to the 1962 Second Century Plan. In that vision, a daylit channel of City Creek would flow “southward toward Downtown and tied into the green areas and tree-lined boulevards of the core” (Second Century Plan 14). The Salt Lake City Riparian Corridor Study lists daylighting as a key opportunity and objective. Plan Salt Lake references daylighting under Natural Environment Initiative 1 to “preserve natural open space and sensitive areas to sustain biodiversity and ecosystem functions through: restoration of aquatic and riparian corridors and habitats (including daylighting of streams and water corridors)” (Plan Salt Lake 27). The Downtown Plan “encourage[s] the continued ‘daylighting’ of creek[s] to link the mountains with the Jordan River…” (Downtown Plan 73). Other plans for Salt Lake City, such as Salt Lake County’s Integrated Watershed Plan and Stream Care Guide and the Wasatch Front Regional Council’s Life on State, among many others, all recommend daylighting.
Maps from the turn of the 20th Century depict Emigration Creek flowing very closely to its current alignment. It is likely that the creek was culverted within its historic channel. By uncovering the creek, homage is paid to the creek that sustained the settlement of this neighborhood in our oasis on the edge of a desert. With efforts to restore the historic sense of the SL Costume Building and signage, the creek could add an extra historic and cultural narrative to this fantastic project. By harnessing the history of place – where the creeks once flowed freely – this project will become a demonstration for additional efforts to uncover the County’s 21 miles of buried waterways.
The Seven Canyons Trust has begun efforts to uncover 1,000 feet of Emigration Creek at Herman Franks Park and 200 feet at the Three Creeks Confluence, downstream of the SL Costume Building. With $1.2 million dollars secured, the Three Creeks Confluence – where Red Butte, Emigration, and Parley’s Creeks enter the Jordan River – will be the first on-the-ground demonstration. Daylighting within this development can magnify current work on the creek, furthering connections between the Wasatch Mountains and Jordan River. There is an abundance of surface parking lots in the neighborhood. Parking lots at The Church of Jesus Christ of Latter-day Saints and Mimi’s Bakery on either side of the SL Costume Building parcel present future opportunity areas for daylighting.
Dolph Creek - Headwaters Apartments
Length: 1,000 feet
Inspiration: Community Amenity, Water Quality, Wildlife Habitat
Developers tore down an old, dilapidated building in preparation for a large development in Portland’s Multnomah neighborhood. A utilities check found an unpermitted culvert running through the center of the parcel. Upon further research, City employees found old maps referring to the waterway as Dolph Creek. Just beyond the property the culvert flows into Thornton Creek.
By taking advantage of existing development, site disturbance, and construction crews, approximately 1,000 feet of creek was uncovered for $200,000. Rocky Mountain Institute’s Daylighting: New Life for Buried Streams estimates daylighting costs an average of $1,000 per linear foot. Utilizing existing crews to excavate the channel, costs were drastically reduced. Fill material was included with other construction debris to reduce dumping costs or used on-site.
The development retains all stormwater. Green infrastructure, bioswales, rain gardens, pervious pavement, and green roofs, work to clean runoff before entering the stormwater system. Additionally, senior and affordable housing was included. The creek provides easy access to nature for these vulnerable populations. The project received a Silver rating from the United States Green Building Council’s Leadership in Energy and Environmental Design.
Thornton Creek - Water Quality Channel
Length: 800 feet
Inspiration: Community Amenity, Economic Development, Water Quality
An overflow, surface parking lot, adjacent to a suburban-style mall, in Seattle’s Northgate neighborhood sat empty for much of the year. New transit-oriented development initiatives highlighted this area due to its adjacency to a regional Bus Rapid Transit station. Urban runoff, from the adjacent surface parking lots, was increasing sediment loads and degrading water quality in nearby Thornton Creek.
With a focus on water quality, the daylighting project used a series of swales and ponds to desilt and retain nutrients in the runoff. Catchment basins slowed water velocity to reduced downstream erosion and flooding. Vegetation has improved the habitat value of the area, while soaking up nutrients through their roots. The project has made tangible benefits to improving water quality.
The project costed the municipality approximately $14 million. However, it has facilitated an astounding $200 million worth of surrounding mixed-use development. The developments took advantage of the interesting, walkable green space, now filled with nature and art installations. All in a former surface parking lot.
The preferred design concept proposes to push the existing parking lot approximately nine feet to the east. By freeing up space, a portion of the flows of Emigration Creek can be brought to the surface in its historic channel. The 75-foot creek would buffer parking from the building, creating an area for tenants to enjoy the waters, relax, and celebrate. The concept would beautify the development and create a pleasant break in the asphalt and concrete-dominate east entrance. There is approximately 13 feet of right-of-way for tenants to navigate through the parking lot and for backing out. Further research shows standards on this vary. The average seems to be about 15 feet. For smaller vehicles, 13 feet is sufficient space. Larger vehicles may occupy parking spaces on the south-side of the building. Signage can be used to clarify. Two feet can be taken from the creek and giving to parking, if necessary. No parking spots would be lost in the process.
There are several design options to lift the creek to the surface. A sculptural fountain would pump water to the surface to then flow into the creek. An Archimedes Screw, a low-energy pumping option, would present a more natural selection. Two screws along the Jordan River are used by Salt Lake City Public Utilities to lift water; the technology is tried and trusted. Lastly, a second culvert could tap the existing Emigration Creek upstream to allow for gravity flow into the creek channel. While this option would not require any energy costs, it would be expensive to construct.
The desired amount of water would be chosen based on channel dimensions. By tapping the culvert, rather than outright uncovering, water levels are highly-controlled. Other than surface runoff from the parking lot, no more water beyond the desired amount would enter the channel. By keeping the existing Emigration Creek culvert in place, any flood concern would be mitigated.
A small floodplain, with riparian plantings, would create a dynamic feature in precipitation events. The floodplain would clean water and filter pollutants before entering the stormwater system. An ADA-accessible boardwalk would connect tenants to the parking lot. Additionally, a paved pathway at the north end of the creek connects tenants directly to the building’s entrance. Benches and seating areas would create pleasant gathering spaces. All other amenities and site designs are preserved, beyond the proposed.
By taking advantage of site disturbance and construction crews, costs can be cut drastically. While crews are rehabilitating the building, as well as upgrading the parking lot and alley, the channel can be cut; an easy process with existing heavy equipment. One challenge with the project will be how to tap the existing culvert. However, with an open and collaborative partnership between Salt Lake County Flood Control, Salt Lake City Public Utilities, the Seven Canyons Trust, and the developers, challenges can be overcome. Rather than spending millions to undue past mistakes, this development presents an exciting opportunity to uncover Emigration Creek for a fraction of the cost.
The alternative design concept proposes to uncover approximately 50 feet of Emigration Creek in existing open space along the north-side of the building. While not in its historic channel, this concept would not require any changes to the site design. The site’s topography allows for a gravity flow westward. An eastbound culvert would bring the waters back to the pipe containing Emigration Creek.
This concept would have the same benefits for residents and creek health. It would also have the added benefit of attracting and educating passersby on 1700 South. It is less likely that gathering space could be included. Benches facing south would look directly at the ground-level unit and those facing north would be hard to access, unless a bridge were included. Alternatively, if gathering space is desired, backless or moveable seating, such as concrete blocks, would allow people to sit in any direction. It is unlikely the creek would take on any runoff from the surface parking lot, unless a pipe directed the stormwater into the channel. Therefore, there would be no stormwater benefits associated with water retention, filtering nutrients, and trapping sediments. Although, these benefits would still apply for the creek water.
This type of green infrastructure is a physical landscape element that removes pollution and contaminants simply by catching water. A bio-swale could be a low-cost option to capture some benefits of daylighting. Surface runoff from the adjacent parking lot could be directed into the bio-swale, slowly draining and simultaneously filtering the water into the ground. This would have the benefit of reducing pressure on the stormwater system.
Another option, or in addition to the bio-swale, would be riparian plantings to buffer the parking lot. Species, such as Fremont cottonwood, Woods’ rose, golden currant, and coyote willow, would provide habitat value. Interpretive signage could teach tenants about the importance of riparian vegetation for migratory birds and other Utah species. However, plantings would be water-intensive without a constant water source. Although, the garden would be somewhat of a mitigation planting for the lost creek.
Local Case Studies
Parley’s Creek - Intermountain Memorial Center
900 E 2000 S, Salt Lake City, UT
While not a daylighting effort, this project demonstrations how to preserve a creek in a confined urban environment, without forgoing a natural channel. Gathering space allows employees to visually interact with the creek during lunch breaks; a daily dose of Vitamin “Nature.” Moreover, the creek is not only an amenity for the hospital, but also the surrounding neighborhood.
City Creek - Canyon Road
150-200 Canyon Road, Salt Lake City, UT
The first daylighting effort in Salt Lake City, City Creek was uncovered through the former grassy median of Canyon Road. This project brings only a portion of the flows of City Creek to the surface in an engineered channel. Natural features, such as embedded rocks and vegetation, benefit in slowing water velocities and soaking up pollutants. This effort has improved property values two-fold.
Unnamed Creek - Arlington Park Planned Development
1075 E 800 S, Salt Lake City, UT
This planned development restored an unnamed headwater stream that flows through the parcel. Developers meandered the stream channel among the townhomes in quite a confined space, creating a beautiful and interesting development. Choke with invasive species, the developers used site disturbance to restore the channel and remove noxious weeds to produce an amenity.
TAC∙TI∙CAL UR∙BAN∙ISM (noun) - Low-cost, short-term projects to catalyze long-term change.
Paint can be used in creative ways to challenge tenants and passersby to think about the concept of buried, culverted creeks. For example, community members assisted in painting a blue, meandering creek channel over top a buried creek running through the Glendale neighborhood of Salt Lake City. A series of prompts, starting with “This would be a good spot for a creek,” guide users through the project and retain interest. Painting efforts are typically short-term to raise awareness for large efforts.
A more permanent solution to paint would be the use of concrete to represent the underground Emigration Creek. One idea is to pour concrete into a meandering channel design, coloring it a different shade to stand out. Prompts, simply depicting “Emigration Creek,” could be pushed into the concrete. Another option would be to chloro-plast more intricate prompts, such as poetry or narratives on the history of the creek and neighborhood.
Installation pieces can visually represent the underground waters. For example, an installation at the Three Creeks Pocket Park used three bridges to represent the three underground creeks flowing near the area. One idea is to put a pipe down into the culvert, so residents could hear the running water underneath.
An architectural or artistic fountain can bring creek water to the surface. This would allow residents to experience the water and creek beneath. A place to gather or relax. Alternatively, recirculated potable water can be used. Although, there would be costs in water usage.
Benches, street-lamps, or other site features could be colored a shade of blue or depict the words “Emigration Creek” to create an aesthetic that plays on the context of the site. Tenants would be able to follow the pathway of the creek through the visual cues.
Various forms of signage, from the temporary – flags or plastic lawn signs – to the more permanent, could be used to educate residents about the presence of Emigration Creek underneath where they live. Signage can be used in conjunction with all of these ideas to frame the context of the efforts.