The complex has been home to various Denver Water operations since 1881, and over time, the buildings became outdated and inadequate to support the operational and administrative needs of the agency. The full redevelopment included the demolition of 15 obsolete and inefficient buildings, renovation of two existing buildings, and new construction of four industrial buildings, a parking garage, a wellness building, and the LEED Platinum and net zero energy administration building.
Denver Water’s 187,000-square-foot administration building pushes the boundaries of what is possible in water efficiency and reuse. (Frank Ooms Photography)
Water Conservation, Efficiency, and Reuse Strategies
The pioneering water conservation and reuse strategies incorporated into the campus are inspired by Denver’s One Water plan, a management framework that fosters collaboration between public agencies that oversee the region’s water systems. The most visible applications of One Water strategies are in the administration building, which features rainwater capture for irrigation and on-site wastewater treatment and recycling.
A key component of the One Water philosophy is the integrated approach to all forms of water: drinking water, wastewater, groundwater, reclaimed and reused water, rainwater, stormwater, and floodwater. The development team included Trammell Crow Company as owner’s representative and master developer, Stantec as project architect, and Mortenson Construction as general contractor, along with a team of more than 200 design and construction subcontractors. Together, they incorporated a wide range of water-smart design strategies. The project aims to use the most appropriate source water for each water use, like rainwater for irrigation and toilet flushing. Other strategies reduce as much water demand and discharge to the environment as possible through recovery and reuse. For example, the project features low-flow plumbing fixtures throughout, rainwater-capturing systems on the roof of the administration building and parking garage, porous paving, bioswales, and a native detention pond on site.
The water recycling system (WRS) is the most unique and innovative element of the campus. Wastewater from restrooms and the cafeteria is diverted to the WRS, an on-site treatment system in which water travels through various closed and open aerobic tanks before routing through a constructed wetland and a final filtration process.
Denver Water headquarters’ blackwater is treated on site through various closed and open aerobic tanks, a constructed wetland, as shown in the photo, and a final filtration process before reuse. (Frank Ooms Photography)
Outcomes
The system is capable of recycling up to 7,000 gallons per day, which is more than enough to meet current demand. The updated campus demonstrates what is possible in water efficiency and reuse.
“We’ve seen across our portfolio that owning and operating high-performance properties is a sound investment strategy that can lower utility bills, improve tenant attraction and retention, and improve net operating income when executed correctly. We really believe this and we’re seeing it adopted more and more widely.” – Lee Ferguson, Vice President, Denver Office, Trammell Crow Company
The Indianapolis Cultural Trail: A Legacy of Gene and Marilyn Glick, a linear park and greenway, began as the brainchild of Brian Payne, president and CEO of the Central Indiana Community Foundation (CICF), who began advocating for the idea in 2000 and saw it through to completion in 2012. The Trail is now operated and managed by a nonprofit named for the greenway, The Indianapolis Cultural Trail.
An eight-mile loop of combined bicycle and pedestrian lanes surrounded by vegetation, with two more miles in development, the Trail connects five main historic or cultural neighborhoods to every significant arts, cultural, heritage, sports, and entertainment venue downtown and to the city’s already-successful greenway and bike system, which had previously not included any on-street bicycle facilities.
As described in a case study by the Pedestrian and Bicycle Information Center and Context Sensitive Solutions, the trail was conceived as a means of economic development and cultural placemaking. The Trail also became an intensive infrastructure upgrade project, which not only built bicycling and walking lanes for access and mobility and added art installations, but also replaced outdated sewers, roadways, and utilities.
As such, the project required millions of dollars in funding, which the city did not have in its budget. Nevertheless, through tireless community engagement and stakeholder meetings with key players, Payne and other supporters were able to secure nearly $30 million in private philanthropy, nearly half of which came from a major donation by Gene and Marilyn Glick, for whom the Trail is now named.
As a major transportation program, several federal grants were also secured, such as the Transportation Investment Generating Economic Recovery (TIGER) grant, to cover $35.5 million in remaining project costs, demonstrating the value of stacking public and private dollars for infrastructure projects with major physical and social benefits to urban development.
The Trail also provides major health and livability benefits by reducing the width of Indianapolis’s car-oriented broad streets, which had allowed cars to speed through downtown, impacting public safety, walkability, and air quality. By borrowing four to 12 feet of lane width in travel and parking lanes and expanding corner bump-outs at every possible location, the Trail significantly improves safety and multimodal transit for all users. Features such as ramps, countdown timers, and audible signals at traffic lights also ensure the entire trail network is universally accessible. A bikeshare program with discounted membership for low-income residents also expands access and supports equitable use of the trail, while supporting low-carbon transportation.
Construction unfolded in seven phases over six years, slowly expanding through Indianapolis. Community engagement was essential along the way—project teams engaged hundreds of residents through public meetings and door-to-door outreach, explaining each phase of the project as it went through a new stretch of the city and gathering input on design. The design team held a four-day charrette for stakeholders from city agencies, elected officials, state Department of Transportation and federal Highway Administration staff, and movers and shakers in local philanthropy, business, and neighborhood groups to build consensus and support and inform the design.
Public art also infuses the Trail, with a call for artists to contribute to the project and installations selected by an advisory committee. Similarly, green infrastructure accompanies the Trail at every turn in the form of an extensive network of bioswales, planted with drought-resistant native plants and trees, that absorb stormwater while enhancing biodiversity and beautifying downtown.
The Trail was ambitious in its multiple goals, as put by Rundell Ernstberger Associates, landscape architects and urban designers on the project:
“This project presented a once-in-a-lifetime opportunity to rethink the city on a variety of levels: reclaim public space once dedicated to vehicles for the exclusive use of pedestrians and bicyclists; provide a universally accessible, safe, and convenient transportation option for everyone from 8 to 80; create a significant and lasting contribution to the natural and built environment with a connective linear park that provides access to beauty and nature every day for everyone; pioneer new stormwater management techniques that minimize the impact to waterways; catalyze smart growth revitalization and economic investment that transforms underutilized properties into mixed-use, mixed-income developments; and achieve greatly enhanced mobility through transit integration and community bike sharing.”
The result was a compelling blend of mobility infrastructure, public realm improvements, and climate resilience features, all of which have contributed to a boom in redevelopment in downtown, where small businesses, shops, restaurants, and real estate development have filled in vacant and underused lots and supported a thriving economy, all protected from increasingly heavy rain and pollutant runoff by the Trail’s impressive bioswales.
Climate Resilience Strategies
As Kären Haley, executive director of the Cultural Trail organization, describes, development of the Trail in and of itself was a major resilience and sustainability strategy to enhance residents’ ability to move around and access their own city. “Investing in this level of pedestrian, bicycle, and people infrastructure is a huge part of the resilience effect of the trail, especially in a city in Midwestern America, where for the most part, people get around by cars.”
An expansion that opened in mid-summer 2024 will expand that impact further. “The city and private philanthropic partners have announced a $50 million investment in building out the rest of the city’s trail and greenway network. That will bring the benefits of walkability out into neighborhoods that generally are not connected to the downtown or to each other by means other than roads.”
Parks and open spaces
The Trail added a total of five acres of linear green space to downtown, which was previously impervious surfaces. These park areas are not only an opportunity to integrate green infrastructure, but also for health and wellbeing as an active recreational resource and placemaking strategy. “The green infrastructure solutions are adding beauty to downtown,” says Haley. “Right now, for example, we have red cardinal flowers growing in most of our stormwater planters. It’s not just that the Trail provides economic benefit for people, and not just environmental benefit, but it makes it a beautiful place to be. And so if you’re able to build that in your community or town or your private development, your employees, your residents, your clients, they’re going to have that same beautiful experience when they walk into your building or they walk onto the property.”
Bioretention swales and rain gardens
The Trail’s stormwater protection features center on the 25,000 square feet of bioswales lining the walking and biking lanes. The swales are sunken in some cases up to two feet deep to maximize stormwater capture capacity, and measure five feet to nine feet wide and anywhere from 12 feet long to the length of an entire city block.
This district-scale system minimized the need for new sewer infrastructure, as it gathers up to four million gallons of rainwater per year. This water then infiltrates into the ground through a natural, unsealed bottom, made possible by the naturally occurring, well-drained, sandy soils, helping recharge local aquifers after cleansing runoff of pollutants. The use of green infrastructure saved the city significant costs in sewage treatment, helping the business case for investing in the system.
It also helps boost the health of local waterways by limiting the occurrence of combined sewer overflows. This was a much-needed improvement after Indianapolis, like many U.S. cities, was placed under a consent decree from the EPA to improve its water quality.
An overflow system was built as a backup to help drain stormwater from an extreme rainfall into the city’s pipes, but in the 10-plus years since construction, Haley noted in a video interview that this added backup has not been needed even once.
As a result, the Trail’s stormwater management system has become what Haley calls “proof of concept” that green infrastructure, and its philosophy of handling water as a resource rather than a nuisance to be piped out as quickly as possible, is feasible at scale in a large city.
Native plants and trees
The planters are filled with thousands of perennial plants and hundreds of shrubs native to the Indianapolis area, which also support local pollinators and wildlife and boost biodiversity. Species were selected for their drought tolerance, meaning little to no extra irrigation or fertilizer is required, lowering chemical inputs and maintenance costs.
Hundreds of trees have also been planted along the Trail, which in addition to the plants and shrubs, contribute to reducing the urban heat island effect by providing shade and natural cooling.
Business Outcomes
Construction of the Trail had a transformative impact on downtown Indianapolis. The Trail is now known internationally as a model for redevelopment focused on multimodal transit and arts and culture, as well as sustainability. In addition to giving numerous tours of its stormwater management system, it has inspired use of similar green infrastructure techniques by other landowners with large properties, such as Butler University and local hospital systems, according to Haley.
Enhanced property value, business development, and capital attraction
Construction of the Trail raised nearby property values by $1 billion from 2008–2014, according to an analysis by the Indiana University Public Policy Institute. Businesses and organizations relocated to be closer to the Trail, and business owners hired additional staff, saw revenues increase, and lengthened their hours of operation in response. The Trail has attracted significant foot traffic, which is a major boost for retail and commercial uses in the area—that same analysis also estimated that, based on surveys of anticipated spending, use of any single segment of the Trail could generate roughly $1 million to $3 million of economic impact. With an initial cost of $63 million, every dollar spent on the Trail created roughly $16 dollars in value.
This is in large part, according to Haley, because of the green infrastructure added to the Trail. “People generally want to be in beautiful places, and they want to be surrounded by lush, vibrant greenery. . . . In terms of creating beauty and quality of place, you can do that with green infrastructure, and it just makes it a more desirable place to be. I think about a road in Indianapolis where the Cultural Trail is, and a road where the Trail isn’t, and the people are on the roads where the Trail is. They’re stopping in those retail locations. They are waving at each other as they walk by. They’re walking into their places of business or their schools. And you just don’t have that foot traffic on those opposite streets that don’t have the Trail. It brings the people, and that investment in nature and beauty is good for everybody.”
Awards and recognition
The Cultural Trail has shone a spotlight on Indianapolis as a leading city with bold vision, and brought numerous awards including the International Downtown Association’s 2013 Downtown Pinnacle Award: Public Space and the Indianapolis Chamber of Commerce’s Monumental Award. The Trail was also included in the New York Times’ list of 52 Places to Go in 2014. The Project for Public Spaces, which supported research and conceptualization of the Trail, noted that “Today, the Cultural Trail has become a global model of how cities can magnify the impact of their public spaces and cultural assets by focusing on the journey and the destination when connecting people to the places they love most.”
Added amenity
The Trail adds significant walking and biking access to the city of Indianapolis, as well as green space, creating opportunities for building health and wellness while accessing the best of the city’s entertainment and cultural venues.
Avoided losses
The stormwater bioswales reduce risk of flooding in downtown by absorbing excess rainwater that may otherwise damage buildings and infrastructure. As the Midwest is projected to see an increase in heavy downpours due to climate change, the ability to manage this stormwater safely is critical.
Lessons Learned
Champions are important: Brian Payne was instrumental in leading the charge on creation of the Trail, and sought donors tirelessly until private philanthropy could pick up half the final bill. Major city-reshaping projects for resilience and urban development benefit from having an advocate who can successfully communicate a big vision.
Collaboration and partnership are key for major projects: The Trail’s development underscores the importance of collaboration between public and private sectors. Pooling resources, gaining public support, and bringing in diverse stakeholders to inform the project were crucial for its success. This lesson highlights the value of fostering strong partnerships to achieve complex urban development goals. Haley notes that partnership is especially important with whichever stakeholder oversees stormwater, whether a utility or municipality to ensure they’re on board with a potentially new or different approach.
Inclusive design and community engagement build support: The Trail’s design process involved extensive community input, ensuring it met the needs of all residents and responded to their feedback when a design change was necessary. Engaging communities early and continuously in the planning process can create spaces that are widely accepted and used, enhancing the project’s long-term success.
Leverage existing spacefor multiple goals: The Trail was a thoughtful solution to Indianapolis’s challenges with excessively wide streets and autocentric design. By repurposing lanes and lane widths not needed for a more multimodal city, the Trail was able to cost-effectively use existing infrastructure to adapt itself to updated ideals for urban design, serving more users, supporting health and wellness, enhancing downtown, and building resilience to heavy rainfall all at once.
When the opening of the Denver International Airport meant the closing of the Stapleton International Airport in the mid-1990s, a coalition of business and philanthropic leaders in the city realized the unprecedented opportunity to guide the former airfield into an environmentally and socially rich “city within a city,” that could continue the legacy of Denver’s historic neighborhoods while creating an abundance of new housing built around a system of parks.
Caption: Central Park’s redevelopment features large open spaces that help restore Colorado’s high prairie ecosystem with native and naturalized plantings.
Jim Chrisman, former senior vice president with Forest City Stapleton and then Brookfield Properties, and now an independent consultant, worked on the project for 30 years and saw it transform from the “Stapleton redevelopment” into the Central Park neighborhood of today. Chrisman notes how the coalition of local civic leaders raised several million dollars to fund creation of a master plan known as the Green Book. The plan was completed in the early 1990s in anticipation of the airport closure in 1995. This plan, ahead of its time as the concept of “sustainable development” was still in its infancy, laid the foundation for and defined the ethos for the project. It also underpinned selection of family-owned company Forest City as master developers for the project in 1998, as recounted by Bill Vitek. Vitek is principal with landscape architecture firm Dig Studio, which has worked on the community’s design guidelines and a large portion of Central Park’s 1,116 acres of parks and open space.
The development’s style, master-planned by sustainability-minded firms HDR and Calthorpe & Associates, leaned more toward a “traditional, New Urbanist design concept where we had a much finer grain of housing types per block and per lot, and not the 40-acre superblocks that you see in the suburban projects” that were more popular at the time, notes Chrisman.
As Chrisman describes, “We pushed the envelope on having alley-loaded product. We went back to the old traditions of Denver, and no one was really doing that, but it really helps with the streetscape. We also pushed really hard on narrow streets.” These small design choices had a major impact on creating a pedestrian-focused public realm.
In addition to the urban design, parks were always central to this style of development. “Nearly 24 percent of the site is parks or open space,” says Vitek. “And the idea was always that if you had such a large percentage of the site being open space, you could do much smaller lots. You didn’t do one-acre lots, or half-acre lots. Even a quarter-acre lot is big out there. The overall premise was to use the community parks and open space as everyone’s backyard.”
Keeping the parks accessible was also embedded in other ways, as the parks are at the front of homes, with a public street in between. “Another decision we made was that no property would back up to the open space. There would always be public right-of-way between open space and houses, so all homes would front open space and everyone would have access to it, which is the exact opposite of the suburban model,” says Chrisman.
Finally, in equal importance to creating a nature-first community was making sure Denverites of many socioeconomic backgrounds could afford to live there. Far from creating a luxury gated community, affordable housing was a key goal from the start: “We [the Stapleton Development Corporation] wanted [affordable housing] integrated throughout the community. . . . We tried to locate it near transit and close to amenities, at modest scale and densities so it wouldn’t be just a big standalone project, and it worked very well,” says Chrisman.
To accomplish this, the master plan called for a diverse mix of housing types, from single-family to townhomes to apartment complexes, and the development also made sure to expand options in other ways: “Our product segmentation was very broad,” Chrisman explains. “We pushed for product diversity from the cheapest builders could build to the highest the market would support. We had a lot of ability for moving up and down.” Partnerships with nonprofit (and later for-profit) developers helped make this happen, as did initial donations of land and $30,000–$40,000 per home to ensure the income-restricted for-sale and for-rent units penciled out. Even today, there are income-restricted units for sale in the $200,000 range—a remarkable achievement in today’s urban housing crisis.
Amidst the impressive development of 12,000 homes and 5,000 apartments, 3.3 million square feet of existing flex/industrial space and 2.6 million square feet of retail, the themes of sustainability and climate resilience remain prominent. Landscape architects Dig Studio developed a network of open space and green infrastructure that prioritized use of native and naturalized plants, restoration of the Colorado prairie ecosystem, and natural management and conservation of water to create a more drought-, heat-, and flood-resistant community that supports wildlife and ecology, while providing a rich set of amenities for recreation, social gathering, and healthy living.
Climate Resilience Strategies
Green infrastructure and flood control
The open spaces at Central Park increased the park system of Denver by an impressive 25 percent. As Laurel Raines, founding principal at Dig, describes it, Central Park’s green space is “a system of parks. And what is really effective about this system is that there’s the layer of the parkways . . . [that] are extensions of Denver’s historic parkway system,” says Raines. “The parkway systems knit the new development back into the existing fabric of Denver.” But that’s not all, as there are also large regional parks like Central Park, which is what gives the redevelopment its name and forms the system’s center at 80 acres. “It’s a very large park. Then there’s all the trunk [or core] open space system, which is run by Denver Parks. The trunk open space system acts as a contiguous fabric through the entire development, and it is primarily a natural system.” Finally, there’s the system neighborhood parks, or pocket parks, which reach as small as half an acre and are meant to give each neighborhood its identity, relates Raines.
Caption: In addition to large core, or “trunk” spaces, the neighborhood features many linear parkways that extend out into the neighborhoods, expanding access to parks while creating biodiversity corridors. Homes front directly onto these parks but do not restrict public access.
This is the heart of Central Park’s resilience strategy, notes Vitek. “Twenty-five years ago we didn’t call it green infrastructure, but it really was serving the same functions. And I think that’s what’s key in any parks and open space planning today is that it has to serve multiple purposes. It has to serve stormwater management and water quality, recreation, ability for greater mobility, and habitat creation.”
In addition to the broad restoration goals, Central Park also naturalized systems for water treatment, quality, and flood control. The south side of the site was in a floodplain, and occasionally airport runways used to flood, so the entire floodplain needed opening up and redesigning. “The first major large open space, Westerly Creek, was designed to take all the pipes that used to go under the ground for the airport and bring them through in a natural waterway through the center of the park and act as a flood control as well as water quality measure. And within the first year or two, the entire calculated drainage area filled up. It was like a lake. It certainly proved the point that it was needed and served its function,” says Vitek.
Caption: This network of large parks, parkways, and neighborhood “pocket parks” offers multiple opportunities to capture and retain stormwater, reducing flood risk and helping recharge groundwater supplies.
Additionally, Chrisman describes how the development team decided to work on a larger scale of water quality management. “We also made a decision that we were going to have regional water quality measures. What you typically see is someone buys five acres and they would have their own small detention pond, and [others do the same] and you have a whole bunch of properties with little detention ponds and it doesn’t look good and I don’t think it’s efficient from a water quality standpoint. We regionalized all that and had regional detention ponds that all properties would flow into.”
When major, hundred-year storms hit Denver in 2013—in Chrisman’s words, “just ridiculous amounts of rain”—the system was tested and passed with flying colors. “That Westerly Creek corridor was able to manage it. There are photos of the water almost up to the bridge, but it managed the water successfully.”
Native plants
The natural landscapes of the Central Park natural system were primarily designed as a restoration of Colorado’s historic ecosystem. Vitek and Raines explain that design guidelines for common and private land prioritize the creation of “Colorado-scape,” an evolution of the idea of xeriscaping, which focuses on use of native and naturalized plants that are adapted to the arid climate and do not need extra irrigation, in place of imported eastern lawn grass species. These plant species also attract pollinators and support biodiversity, and studies show they help with the urban heat island effect, because their roots are so much deeper than lawn species that they help more water evaporate from the soil and cool the area. Finally, they do not spread weed seed into the National Wildlife Refuge, which is adjacent to the neighborhood.
Caption: Landscape design focused on plants suitable to Colorado’s ecosystem, which would support pollinators and the larger food chain while also helping reduce water use for irrigation and enhancing the parks’ ability to cool their surroundings.
This evolution, as Vitek describes, was a shift in philosophy from the City Beautiful movement that shaped Denver in its early days, based on eastern U.S. designers’ ideals of lush lawns, to what he calls the “City Ecological” ideal focused on the no-less-beautiful but more appropriate local aesthetic of Denver’s high prairie landscape. This focus has rewarded people and nature, providing what Vitek calls “an opportunity not only for connective recreation, but connective habitat,” as they even saw beavers move in shortly after the fences came down around the old airfield.
As Colorado has experienced greater challenges with water scarcity, the landscaping selections have become more water conscious. “The old guidelines from the south and the new guidelines from the north [of the development] are different. For instance, just the plant palette alone that is suggested is more water conserving than it used to be,” says Raines.
In addition, these native and naturalized plants also include tens of thousands of trees (nearly 40,000 officially, and Vitek and Raines suspect it may be closer to 50,000) that also help cool the area, support biodiversity, and enhance human mental wellness through their biophilic benefits.
Reclaimed water
Lastly, the area uses Denver’s reclaimed water system, also known as purple pipe water (sewer water that has gone through sufficient treatment for nonpotable reuse). This water now irrigates the larger parks in the system, significantly reducing water withdrawals for irrigation.
Energy efficient buildings
As a key aspect of sustainability, many buildings in Central Park have been designed to LEED standards or Energy Star requirements. By virtue of these achievements, Central Park has become the largest Energy Star community in the state.
Value Creation
Added amenity and enhanced user experience
The parks and open spaces create significant amenity value for Central Park as places for recreation, exercise, and connecting with nature, improving quality of life for residents and Denverites and attracting large numbers of users.
Avoided losses, energy savings, water savings, and reduced operational costs
The natural flood control and floodplain protection measures significantly reduce the potential for property damage from heavy storms and river flooding. Additionally, the high level of energy performance required for buildings and the drought-resistant plantings both reduce energy and water use and associated utility bills for residents and owners.
Awards and recognition and marketing advantage
As development has unfolded, Central Park has attracted numerous awards, including a 2006 ULI Award for Excellence, a U.S. EPA Environmental Achievement Award, and the prestigious Stockholm Partnerships for Sustainable Cities Award from the King of Sweden, among others. This recognition as an international model for large-scale, sustainable redevelopment creates significant competitive advantage and marketing opportunities.
Business developmentand enhanced property value
The high-quality design and execution of the homes and communities in Central Park have created high demand and a strong pool of occupants. From 2010–2019, Central Park appeared six times in RCLCO’s lists of the year’s top 10 best-selling master-planned communities in the United States. As Vitek notes, “study after study will show that communities that have more parks have a higher premium value for properties and sales. . . . Additionally, Central Park stood the test of time during the COVID-19 pandemic, because sales there continued, while in other places they really dropped off.”
Raines and Chrisman both highlight that resale within the neighborhood is one of the biggest sales pools, constituting 40–50 percent of sales every year and demonstrating a high level of satisfaction and desire to remain in the neighborhood. As Raines puts it, “This is a beloved neighborhood. It’s very common for people to move from one house to another, to another.”
Although in a large, master-planned community it can be hard to attribute success to a single factor such as parks, Chrisman believes it has much to do with the exceptional amount of green space created. Though he notes the location was hampered by an Air Force base to the south, an Army medical hospital to the east, and an Environmental Protection Agency Superfund site to the north, the parks were able to overcome those barriers. “They really did create value in the long run, especially with the way we had the houses fronting the parks. It created immediate value for their homes as well as overall value, because it created demand for people to want to be there. And there’s no way to prove it, but if we’d had only 400 or 500 acres of parks [instead of the 1,100], I don’t think it would have done as well.”
Lessons Learned
Embed sustainability from the beginning. Central Park’s champions, the group of leaders in the Stapleton Redevelopment Foundation who began the master-planning and development process, were committed to environmental and social performance from the start and ensured the execution matched the original vision of the Green Book. Sustainability is best achieved when it informs every choice made throughout a development’s life cycle.
Find the right partners. Similarly, sustainability can be difficult to carry out unless all partners throughout the value chain are committed. The Foundation was able to find the right development partners, from Forest City and Brookfield to design consultants Dig Studio, HDR, Civitas, and Calthorpe & Associates, to the multiple builders involved, to align on aiming high for the redevelopment.
Design for the long term, even if ahead of one’s time. Sustainability is still not mainstream in real estate, but when the redevelopment planning began in the early 1990s, sustainability was far from reaching the levels of acceptance it has today. Nevertheless, the development team realized its potential as a strategy to create lasting value, and as modern demand for ecologically and socially oriented communities continues to rise, the development is well-positioned to capture even greater value.
The Aurora Bridge is an essential piece of Seattle’s transportation infrastructure and carries more than 65,000 vehicles through the city per day. During the city’s frequent rainstorms, chemicals from the roadway are cast into the waters of the Lake Washington Ship Canal below. This untreated runoff—which researchers say is six times more toxic than the national standard—flows directly into local waterways, harming the health of local ecosystems, economies, and communities.
As climate change increases the severity of Seattle’s rainstorms, the volume of stormwater runoff is expected to grow. According to research commissioned by Seattle Public Utilities (SPU), extreme rainstorms have become 30 percent stronger since 2003 and are projected to intensify over the coming decades. Heavy rainstorms are already overwhelming the sewer system’s capacity in many neighborhoods, triggering flooding and toxic overflow into local waters.
Developers Mark Grey, Joanna Callahan, and Mike Hess of Hess Callahan Grey Group (HCG) were inspired to do their part after learning how polluted stormwater affects local wildlife. They had watched a video of baby salmon dying when put directly into water runoff from a nearby bridge. The video then showed the runoff being filtered through soil before introducing the fish, resulting in none of the fish dying. The video demonstrated the power of natural systems to mitigate the effects of toxic stormwater.
This knowledge led HCG to partner with Salmon Safe, a local organization working to protect waterways, to integrate green infrastructure into two commercial office projects they were developing on a steep slope under Aurora Bridge. Given the unique location, the project team saw an opportunity to collect and treat the bridge’s runoff while improving the adjacent rights-of-way along Troll Avenue, directly underneath the bridge. Dark and unwelcoming, these overlooked tracts of land were mostly empty except for the streams of polluted water that were spilling out of downspouts from the bridge above.
The team installed the bioswales in three phases. The first two phases, which line Troll Avenue, were financed and permitted as part of the two office projects’ frontage improvements. The third phase, which sits down the hill and closer to the lake, was developed thanks to a nonprofit, Clean Lake Union, formed by Mark to advocate for continued clean-up efforts around the lake. Many public and private partners also contributed to the third phase, including Salmon Safe, The Nature Conservancy, Boeing, Tableau, Adobe, Seattle Public Utilities, and the state of Washington. Together, these three phases collect and treat up to two million gallons of water annually from the entire north span of the Aurora Bridge, minimizing the risk of neighborhood flooding and improving water quality.
HCG worked with project architect Weber Thompson and engineering firms KPFF and DCI Engineers to bring the swales to life. “The most exciting thing about this project,” says Rachael Meyer, landscape architecture principal and director of sustainability at Weber Thompson, “is that it has convinced so many people that green infrastructure is a viable solution, and it has paved the way for future projects of this kind to be developed throughout the region.”
Climate Resilience and Sustainability Strategies
Bioswales and natural stormwater management
The bioswales harness the power of nature to help collect, filter, and absorb stormwater before it is discharged into the lake. Six downspouts located under the Aurora Bridge carry runoff from the roadway into planted areas. The runoff flows through the swales before being returned to the municipal storm drainage system that discharges into Lake Union.
The swales in the first two phases, located on either side of Troll Avenue North, are terraced and step down every two feet of grade. At each stage, low dams made of Corten steel hold and slow the movement of water so that sediment and contaminants can be filtered into the soil, while the clean surface water outfalls to the next retention cell. The second phase also features staggered concrete walls, which help slow runoff from the adjacent building and promote evaporation. A block downhill, phase 3 is characterized by a spillway and five low steel walls to settle and divert incoming water before it reaches the lake.
Testing of the water entering and leaving the swales confirmed measurable filtration of a large range of contaminants.
The design incorporates consecutive swales down the steep hillside of Troll Avenue. As water flows through the swales, sediment in the runoff settles into the soil and the cleaned water at the top of the pool flows to the next stage. Image credit: Built Work Photography
Native Plants and Biodiversity
All three phases incorporate a variety of native plants and trees that provide both an aesthetic landscape and play an important role in stormwater management. Vegetation slows down the movement of water and filters sediment and other large particles. Plants also support healthy soils, which contain microbes that digest contaminants and other tiny particles.
The project team prioritized pollinator habitat by including flowering plants and designing flat areas within the swales where bees can find water and shady respite in the summer months. Native vine maples, which are often found in the understory of Pacific Northwest forests, add shade in the summer months and color in the fall.
Most critically, water that has made its way through the swales is visibly cleaner, promoting the health and longevity of five different species of migrating salmon that travel through Lake Union on their way to rivers and streams for spawning. Salmon are foundational to the region’s natural environment, fishing industry, and the cultural identity of local Native American tribes. As indicator species, they provide a signal of the overall health of the Pacific Northwest marine environment.
Native shrubs and Vine Maples serve as understory plantings to provide a robust forest floor below the overhead canopy that the bridge structure and columns simulate. Image credit: Built Work Photography
Green space and public access
Through the addition of native plants and natural features, the swales have enhanced two rights-of-way on Troll Avenue North as well as a previously grass-covered tract of land closer to Lake Union. Prior to the swales’ development, these areas were dark and forgotten, always in the shadow of Aurora Bridge above. Today, the swales open up the streetscape and provide a new place for the community to congregate in formerly degraded areas.
Educational signage in the first two phases engages visitors with the story of the swales and the importance of water quality on the region’s salmon species. Phase 1 also has embedded brass numbers in the sidewalk that show visitors the volume of water cleaned annually in the adjacent swale cell. The steel weirs in the third phase feature silhouette cutouts of the five species of salmon that reside in the nearby waterways.
The swales are centrally located in the heart of the Fremont neighborhood, known for its quirky shops, unique restaurants, and the iconic Fremont Troll, an 18-foot cement art piece that has lived under the Aurora Bridge since the early 1990s. Down the hill, next to the phase 3 swale, is the Burke-Gilman Trail, which serves more than one million pedestrians and bicyclists annually. Throughout the year, thousands of people travel beside the swales on the Burke-Gilman, on the way up to the Troll, or down to the waters of Lake Union.
Value Proposition
Added amenity
The bioswales transform previously dark, vacant areas into well-lit, landscaped destinations that people are eager to visit and enjoy. Lined with native plants, the meandering pathways, plazas, and benches invite visitors to gather, take photos, and spend time observing the natural flow of water through the swales. “People stop and appreciate the bioswales even without really knowing what the system is doing to protect the neighborhood and improve water quality,” said Meyer.
Reduced maintenance costs
Prior to the swales, the area that is now phase 3 was covered in grass, requiring regular mowing and upkeep. Today, minimal maintenance is needed beyond an occasional weeding. In addition, nearby property owners have reported reduced instances of vandalism since the swales were installed, reducing the need for frequent repairs and upkeep.
Awards and recognition
The bioswales have been recognized by numerous organizations for their unique design and success delivering environmental benefit through a unique public/private partnership.
ULI Global Award for Excellence Winner, 2023
ULI Americas Award for Excellence Winner, 2023
2022 GRAY Magazine Awards, Grand Winner: Landscape Design
2022 Gold Nugget Awards, Merit Award: Best Landscape Architecture for a Community
2022 WASLA Awards, Honor Awards: General Design, Private Ownership
2019 King County Green Globe Award: Leader in Water Quality Solutions
2018 WASLA Awards, Phase 1: Vision Award for Water
A case study of this project is included in a United Nations Guide for Sustainable Practices to teach professional designers ways to include green infrastructure as a standard practice.
Staggered concrete walls help slow runoff and promote evaporation, reducing the amount of water flowing into the swale. Image credit: Built Work Photography
Lessons Learned
This project demonstrates how privately funded green infrastructure can be leveraged to improve public roadways, especially bridges, and provide community benefit. Prior to the Aurora Bridge swales, few precedents existed for private developments electing to clean roadway runoff as part of frontage improvements. This type of development was not originally allowed outright in the city’s code but has now paved the way for more streamlined permitting of future swales across the city. In addition, the success of the Aurora Bridge swales has inspired Seattle Public Utilities to establish programs to incentivize similar improvements as partnerships with private developments.
The project team has observed that the bioswales are dry most of the time, indicating that less space is needed to collect and filter the bridge’s runoff. This means that the system’s capacity can keep pace as Seattle’s rainstorms become heavier and more severe. Climate predictions for the Seattle area indicate that extreme precipitation events are likely to be more intense. For example, the magnitude of the average 25-year storm is expected to increase by 13 percent by 2050 and 12 percent by 2090.
The bioswales offer a replicable model for other communities looking to leverage green infrastructure to improve stormwater management and water quality in urban settings. The regulatory environment around stormwater management is complex, and the team had to navigate numerous requirements from various public agencies at the city, state, and federal level. In particular, the project had to secure special approval to divert roadway catch basins and downspouts into the right–of–way temporarily before returning the water to the storm drain system. Despite these hurdles, the success of the bioswales demonstrate the importance of collaboration among these agencies to realize significant community and environmental benefit.
Alys Beach began design in 2003 as a labor of love by EBSCO’s cofounder, Elton Bryson Stephens, Sr., who bought the land in the late 1970s and named the future community after his wife, Alys. The area, known locally as 30A after the scenic highway running through it, and its beach resort communities are a treasured destination across the Southeast, with increasing recognition in other regions. Most homes in Alys Beach started as vacation homes, but post-COVID, many homeowners took up year-round residence.
Alys Beach stands out for its award-winning New Urbanist design, created by some of the founders of New Urbanism itself—DPZ CoDesign, the firm established by Andres Duany and Elizabeth Plater-Zyberk, in collaboration with and carefully maintained by town architects Marieanne Khoury-Vogt and Erik Vogt, who have added their own flair and influences from Moorish, Greek, and other vernaculars.
As Galina Tachieva, managing partner at DPZ explains, Alys Beach was informed by the earlier, nearby DPZ projects of Seaside (already famous by the time) and Rosemary Beach, and can be understood as a third generation of sustainable and resilient developments that prioritize compact, walkable, pedestrian-scaled communities filled with open spaces and public gathering areas in the style of older, pre-automobile cities around the world. “The compactness of these communities is the number one condition for being environmentally responsible, because then you can leave nature alone,” she notes.
Storm resilience was also an obvious necessity, given the location and the community’s origins. “The Stephens family was committed to this as a legacy project and was not going to take shortcuts, and understood the need to invest on the front end,” according to Khoury-Vogt. Developer and designer visions aligned, and when DPZ was brought in, “it became really important that sustainability was considered on all aspects of the project from the horizontal infrastructure to the vertical infrastructure.”
As described by Allan Barnes, president of Apex Engineering Group, every structure is designed to withstand wind speeds over 160 miles per hour, or a Category 5 hurricane and an F3 tornado. Homes near the water are built to the ASCE/SEI Standard 24-14, Flood Resistant Design and Construction, and the guidelines of FEMA P-550, Recommended Residential Construction for Coastal Areas: Building on Strong and Safe Foundations, using deep pile foundations and site walls that can endure wave impacts, scour, and erosion. All told, the site is prepared to experience “extreme storm event-related erosion and scour” and “the dynamic wave set-up and surge elevation of a 100-year storm event.”
Climate Resilience and Sustainability Strategies
Alys Beach uses a combination of green infrastructure/site strategies and building strategies to achieve a resilient design that responds to its main risks of hurricane winds and extreme heat, and in extraordinary cases, storm surge.
Alys Beach is located roughly 30 feet above sea level behind preserved natural dunes, which protect the community from storm surge. The community continually replenishes the dunes to maintain them as an important coastal habitat and resilience measure. Courtesy of Alys Beach.
Grade elevation and access
“We’re lucky here that we have a natural elevation that’s about 30 feet above the water, so we’re relatively inoculated against floods,” says Khoury-Vogt.
Preserved natural features
The master plan preserved the site’s original coastal dunes as the first line of defense, as well as 20 acres of existing wetlands on the opposite, inland end. The community regularly replenishes these dunes to ensure they remain functional for aesthetics and protection.
Green infrastructure and landscape features, and natural drainage system
In addition to these preserved natural features, designed green infrastructure permeates the entire site. All pavement is permeable, and the underground stormwater management system treats all on-site runoff, preserving local water quality and reducing maintenance. The design carefully spread an interconnected collection of smaller detention and retention strategies throughout, from small ponds and bioswales to vegetative buffers and rain gardens.
The site’s natural drainage system replicates historical hydrological pathways. Courtesy of Alys Beach.
This design precludes the need for large detention ponds and creates a natural drainage system, mimicking the site’s predevelopment hydrological pathways, allowing storm and floodwater to move in and out much as it would naturally. The main streets are perpendicular to the beach, preserving all sight lines and providing storm surge a safe way to drain out of the community.
All homes are required to manage their stormwater discharge on site before it enters the community stormwater system, reducing its burden and the likelihood of flooding in Alys Beach and nearby. Only native plants, shrubs, and trees are used, which are suited to the stormy region and require far less irrigation and maintenance than conventional lawns.
Wind-resistant construction
The site’s need for storm resilience led to selection of the FORTIFIED for Safer Living® program, which every structure in the community is required to build to. The program builds on decades of IBHS research on wind vulnerabilities and exceeds the already-strict Florida and South Florida building codes, but wasn’t far out of reach based on the initial design vision.
“One key decision that was made early on for the architecture at Alys were shallow eaves, a huge plus in terms of the potential wind uplift, and the use of concrete tiles on the roof and a five-part system on top to weigh it down. Between that, the impact-resistant doors and windows, and the reinforced masonry block being the essential building block for Alys, we were 90 percent there in terms of adhering to those standards,” notes Khoury-Vogt.
The system effectively reduces the potential for wind damage by tightly fastening the entire building structure—foundations to walls to roofs—together to provide a continuous path for wind forces to follow, eventually transferring safely into the ground.
Impact-resistant, hardened materials
Hardened materials, such as concrete masonry units or cast-in-place concrete walls and concrete roof tiles, play a huge role (though all that concrete does increase the project’s embodied carbon). Khoury-Vogt says, “You can shoot a two-by-four at 150 miles an hour and you’re not going to penetrate your building envelope.”
Cool surfaces and heat-prepared exterior
The all-white coating on every structure reflects solar heat, keeping building interiors and the neighborhood cooler while evoking traditional settlements in hot places, such as Santorini or Tangier. The masonry construction also has high thermal mass, helping it absorb heat and keep indoor temperatures down.
Strategic building orientation and density
Importantly, in addition to concentrating buildings on the site to preserve natural features, Tachieva says, “the streets are perpendicular to the beach, which invites natural breezes up along every street and deep into the site,” keeping the entire community cooler. “This was a technique not used before Seaside, and later Rosemary Beach and Alys Beach—it was either townhouses or concrete towers and slabs parallel to the beach, to have the most views, but blocking everyone in the back.”
Streets run perpendicular to the water throughout the community, allowing natural breezes to circulate, permitting stormwater to drain out naturally, and preserving Gulf Coast views for all residents. Courtesy of Alys Beach.
Thermal comfort is paramount, and the aesthetics are inseparable from climate-smart design. For example, DPZ brought the patio house style from Antigua Guatemala as the basic home typology to mass the home around lot edges, creating beautiful and “very occupiable” internal courtyards, as Erik Vogt describes.
Open-air courtyards in the center of homes and blocks, a design not common in the United States, keep homes cool and provide a sheltered outdoor space. They have become one of the most treasured aspects of life in Alys Beach, helping support strong property values. Courtesy of Alys Beach.
These are shaded but ventilated, and protected from storm winds and waves by reinforced walls. Common versions of these courtyards are also found at the center of many blocks. The patio or courtyard design is more common outside the United States, but Vogt says residents “. . . have really grown to love it. Now that’s become the most important part of the design for most of our clients.”
Low-carbon design
Though it does so quietly, Alys Beach has also emphasized low-carbon design. Vehicle parking is minimal and concentrated at the edges of the development, and extensive trails, smaller buildings, narrower street widths, and public greens make walking the most pleasant option. As Tachieva notes, this approach built on the early success of Seaside, where residents used their cars six to eight times per week, compared to six to eight times per day in nearby conventional developments. The nearly car-free environment not only supports the resort feel, but also reduces vehicle heat, transportation carbon emissions, and air pollution.
Buildings are tightly insulated and carefully ventilated, and use low-E windows. Designers also took the important step of sealing and insulating the attic, reducing heat gain. The white roofs also reduce energy consumption for air conditioning significantly.
Some homes even have solar panels and geothermal heating and cooling systems installed that further reduce carbon emissions.
As Vogt puts it, “What’s grown in importance, as much as the resiliency of construction, is the resource efficiency over the course of Alys’s lifetime, as the public’s understanding of climate change has grown. People appreciate that now almost as much as the durability.”
Value Proposition
Enhanced property value
First and foremost, Alys Beach has achieved some of the highest property values and sales prices in the state. Tachieva explains, “Per square foot, they are close to Manhattan prices, which is quite unusual for lots which are 20 to 24 feet wide by 60 feet long. These are multimillion dollar houses.”
Tess Howard, vice president of community and development planning at Alys Beach, agrees, and credits the FORTIFIED certification as helping secure the premiums needed: “Building in the FORTIFIED standard and the additional certifications helped to establish that level of quality so that we could demand the prices necessary to make the project come to fruition.”
Marketing advantage
The peace of mind provided by the exacting standards is also critical for boosting marketing and sales, and Howard explains that Alys Beach attributes its steady sales prices and volume in part to the quality of construction and FORTIFIED standard, and their ability to assure owners that their sizable investment will be protected.
Though the aesthetics and lifestyle attractions are top of mind for potential buyers, according to Diana Lane, director of public relations at Alys Beach, buyers’ interest and confidence grows after learning they won’t suddenly need to rush to board up their homes before a storm thanks to the property’s resilience features.
Reduced insurance premiums
Alys Beach’s design has also secured owners lower insurance premiums, an outcome that shouldn’t be underestimated given the increasing insurance crisis in Florida and other high-risk areas. “The insurance market for condos, is really, really intense,” says Howard. “The good thing is you know all of our condos are developed really responsibly, so when we are getting those milestone inspection reports and reserve studies done, we are faring well on the contributions recommended.”
However, she and Khoury-Vogt note insurance premiums have still increased tremendously and believe they should be lower, given Alys’s performance against storms.
Avoided losses
Alys Beach should also see far greater avoided losses and lower repair and replacement costs. Alys’s designers intended it to last for centuries, and that means avoiding the unsustainably expensive and disruptive cycle of destruction and rebuilding that has come to define life in many coastal communities.
Lessons Learned
Consistency is key. To maintain community protection and its reputation for safety, each and every building needs to meet the high standards it relies on. The town architect, onsite general contractor, and approved builders are key to carrying forward both the strong design vision and excellence in resilience.
A good pilot can make the business case. Though being an early adopter comes with challenges, Alys Beach’s success as the world’s first FORTIFIED-certified community showed the value of that program locally and built an attractive set of returns for other developers to take note.
Resilience and aesthetics work better together. Many who work on Alys feel that the design lent itself well to a resilient product, while serving as a major value add. The all-white look is iconic, the vernacular architecture is dreamy but functional, the masonry is durable and lends a premium feel, and the courtyards and green infrastructure add extensive amenities and provide climate benefits.
Austin’s Waller Creek Tunnel, completed in 2017, captures floodwater and releases it into Lady Bird Lake, reducing the size of the floodplain along lower Waller Creek and helping revitalize the eastern part of downtown Austin, called the Waller Creek District. The tunnel is about 5,600 feet long, lies 70 feet below the surface, and ranges in diameter from 22 to 26 feet.
Construction of the tunnel has enabled businesses, governments, and nonprofits to invest in the Waller Creek District. The City of Austin, the Waterloo Greenway Conservancy, and the Waller Creek Local Government Corporation created a vision for the district to guide that investment. A mix of private and public projects is in the works for the district, including 35 acres of parks and open space.
The Waller Creek Tunnel was funded through tax increment financing (TIF). The Waller Creek TIF only uses funds generated by the increased property values and property taxes in the Waller Creek District. The TIF not only paid for the tunnel, but also helped fund the redevelopment of Waterloo Park. The Waterloo Greenway Conservancy, the TIF, and the City of Austin are also funding a chain of parks and trails along the creek, called Waterloo Greenway.
Since opening in August 2021, Waterloo Park has welcomed tens of thousands of visitors to explore nature, gather with friends and family, and immerse themselves in musical, cultural, and performing arts experiences. The park includes the new Moody Amphitheater, a 5,000-person outdoor concert venue; an 11-acre green space with a native plant garden; a constructed wetland and terrace next to Waller Creek; walking and biking trails with a skywalk, traditional and nature playscapes; and dedicated space for local food trucks. Waterloo Greenway Conservancy offers free weekly community programs and year-round special events at the park, providing an accessible space where Austinites can relax, have fun, and connect with one another.
Reinvestment along Waterloo Greenway is focused on transforming lower Waller Creek from the site of eroded, polluted, and flood-prone channelized infrastructure into a natural oasis for both humans and habitats. With the addition of the tunnel, the creek conveys less stormwater, allowing it to look and feel more like a natural stream system and take on a new role in downtown Austin. The Waller Creek project invests in public open space, trails, and ecosystem rehabilitation, enhancing access to nature and health in downtown Austin and enabling future resilient development.
Resilience Strategies
Stormwater management. The addition of the Waller Creek Tunnel removed more than 28 acres of downtown Austin from the floodplain, providing opportunities for redevelopment in the Waller Creek District. The tunnel also reduces Waller Creek bank erosion during periods of flooding and gently pumps lake water back into the creek to keep it flowing during dry times.
Green infrastructure. Investment in green space and ecosystem restoration along the Waterloo Greenway helps manage stormwater and flooding, rebuild ecosystems, and enhance access to nature and health for Austinites. The addition of green infrastructure also helps mitigate the urban heat island effect and improve air and water quality.
Native plants. To create an ecologically robust riparian corridor, the Waterloo Greenway Conservancy has focused on saving and adding native plants to the greenway. In Waterloo Park alone, 95 percent of the 90,500 plants and trees are native and 5 percent are adaptive. In the next phase of redevelopment, the conservancy plans to add about 200,000 native plants and 1,500 trees along the greenway from Fourth Street to Lady Bird Lake. The focus on native plants supports local habitats and pollinators, ecological diversity, ecosystem restoration, and resilience to heat, drought, and flooding.
Water reuse. Waterloo Park uses Austin’s reclaimed water instead of potable water for subsurface drip irrigation and toilet flushing, allowing water and energy conservation and drought resilience. The park also has a 50,000-gallon cistern to capture rainwater for reuse.
Value Proposition
Added amenities. The addition of the Waller Creek Tunnel and redevelopment of the 1.5-mile Waterloo Greenway, including Waterloo Park, have added significant value to downtown Austin. Waterloo Park’s new amenities—Moody Amphitheater, an 11-acre green space, walking and biking trails, playscapes, and programming—provide an accessible space for Austinites to relax and have fun.
Avoided losses. The Waller Creek Tunnel significantly reduces flood risk between 12th Street and Lady Bird Lake. Previously, flooding and erosion along Waller Creek were regular occurrences.
Reduced insurance premiums and improved insurance ratings. The Federal Emergency Management Agency (FEMA) floodplain map of the area was updated in 2022 to reflect the improvements. With reduced flood risk, properties in the Waller Creek District are expected to see reduced insurance premiums and improved insurance ratings. Lenders may still require flood insurance, however, and businesses and residents may also choose to keep their flood insurance for financial protection.
Increased developable land. The Waller Creek Tunnel removed more than 28 acres of downtown Austin from the floodplain, providing opportunities for redevelopment in the Waller Creek District.
Capital attraction. Because of the tunnel, businesses, governments, and nonprofits are now able to invest in the Waller Creek District. A mix of private and public projects is in the works for the district, including billions of dollars in private development.
Enhanced property value. Reduced flood risk and high-quality amenities will lead to enhanced property values in and around the Waller Creek District. The investments in the area are expected to increase downtown tax revenue.
Water savings. Waterloo Park’s use of reclaimed water and rainwater instead of potable water for subsurface drip irrigation of the 11-acre green space will result in significant water, energy, and cost savings.
Awards and recognition. Waterloo Park received the ULI Austin Impact Award for Best Public Place in 2022 and the Waterloo Greenway received the ULI Austin Impact Award for Next Big Idea in 2019. Moody Amphitheater achieved four stars in the Austin Energy Green Building rating system in 2021.
Lessons Learned
Vision and planning
The City of Austin and Waterloo Greenway Conservancy staff note that having an exciting and engaging vision upfront was vital to get people on board with the long-term project. “You really have to think about the full life cycle upfront when you’re starting a project like this,” said Kristin Pipkin, project management supervisor for the Waller Creek District Program in Austin’s Watershed Protection department.
This project started with a framework plan that served as a proof of concept for the Austin City Council. Once that plan was approved, the city held a national design competition in 2012, which led to the selection of a design plan that was amended in 2018 and is now referenced in the city’s comprehensive plan.
Within the partnership, planning was essential to figure out the phases of construction, budget timelines, scopes of work, and how to work together across organizations and departments.
Public/private partnership
“It takes a village to make a project of this size and complexity happen,” Pipkin said. While the city was responsible for the tunnel project, partnering with a separate organization responsible for the Waterloo Greenway over time as well as fundraising for capital improvements proved important for the success of the multi-tiered project.
Waterloo Greenway Conservancy was created for this purpose in 2010 to respond to citizens advocating for park and trail redevelopment along Waller Creek. In 2014, the partnership was formalized by a joint development agreement. The convervancy and city recommend engaging in a partnership agreement upfront so that each organization knows what it is responsible for and how best to work together. They also recommend allowing for adaptability, flexibility, and contingencies.
In the case of this partnership, the city is responsible for the Waller Creek Tunnel and owns the land, watershed, and public improvements. The Waterloo Greenway Conservancy is an independent nonprofit responsible for fundraising, design, construction, programming, operations, and maintenance for the Waterloo Greenway. The Waller Creek Local Government Corporation is the approval body for contracts, budgets, financing, design, construction, operations, and maintenance, and is given authority for oversight of the district by the city council.
Political and financial champions
It was clear from the beginning that to develop a project of this scale, it was necessary to have champions with standing and respect in the community who could pull political weight. Leadership from the city was important for the cross-department collaborations, but champions from the community were needed to justify the time and costs of the project. Having a grand vision and plan was helpful for getting community buy-in and sustained interest.
The redevelopment intersected with various interrelated issues, such as infrastructure, private development, utilities, building codes, transportation, affordability, growth, resilience, history, accessibility, and safety. These issues attracted more interested parties and required upfront, transparent communication about what was happening with the project. As an example, the city is working with developers on voluntary design guidelines within Waller Creek District that support Waller Creek. Ongoing communication efforts include public relations, partnerships, signage, programming, and public art.
Sustainable funding sources
With a project of this magnitude, significant and sustained funding mechanisms are required. The Waller Creek Tunnel was a $163 million TIF investment. Redevelopment of the 1.5-mile Waterloo Greenway, including Waterloo Park, is estimated to cost around $265 million over three phases and will be covered by TIF, funds from the U.S. Army Corps of Engineers, park bonds, drainage utility fees, development fees, city budgets, and private partner fundraising. Once the greenway is redeveloped, Waterloo Greenway Conservancy will be responsible for operations and maintenance, which will be covered by programming and concert revenue, philanthropy, and a partnership with the Austin Downtown Alliance business improvement district.
The project partners recommend determining upfront the financial mechanisms—such as TIF, improvement districts, taxes, fees, and/or community partnerships—and building them into the project from the beginning. So far, the selected financial tools are working for the Waterloo Greenway.
ULI is grateful for the support of The JPB Foundation.
Over the last several decades, Boston Harbor has seen asharp increase in the number and intensity of extreme events, with 100-year storms and even 500-year storms becoming more common every year. A 2016 study from the Boston Research Advisory Group (BRAG) states that by 2050, sea levels may be as much as 1.5 feet (0.45 m) higher than they were in 2000, and by 2070 they may be as much as 3 feet (0.9 m) higher than in 2000.1Higher sea levels increase the frequency of dangerous high-tide flooding, increase the intensity of storm surges and wave height, and erode shorelines.This type of sea-level rise could be devastating for large areas of the city, nearly half of which was built on low-lying landfill just above the high-tide line.
The city also lacks a robust seawall, making waterfront properties even more vulnerable to flooding during storm events and high tides. As a result, when Lendlease acquired the 12-acre (4.8 ha) waterfront site, five acres (2 ha) of which are watersheet (tidelands), the firm had a lot to consider. A desire to build an asset that would operate successfully for more than 100 years drove the project team to embed resilience and sustainability into all aspects of the development. After conducting robust climate risk analyses and engineering studies for the site, it became clear that innovative solutions were necessary to ensure that the property—and its 1,700 linear feet (518 m) of harborfront—weathered future storms.
In the early 1800s, the site was home to East Boston’s historic shipbuilding and maritime industry, and throughout the years had seen a variety of uses. Since the 1990s, the parcel had served as a parking lot and consisted of vegetation intermingled with dilapidated wharf structures and piles. Lendlease acquired the site in March 2016 and began construction in August of the same year.
The development consists of 478 residential units across four structures: two condominium buildings with 194 residences and two apartment buildings with 284 market-rate rental units. The site also contains 30,000 square feet (2,800 sq m) of common, amenity, and public areas, including three retail outlets. A central courtyard space anchors the site and features a variety of amenities for both residents and the public, including a large amphitheater, a dog park, art, and natural plantings. The development also knits together a section of Boston’s 43-mile (69 m) Harborwalk system, connecting the project with the broader neighborhood and providing active transportation opportunities along the waterfront.
It was important for Lendlease to invest in the East Boston neighborhood—not only through the amenities and design of Clippership Wharf, but also through the provision of affordable housing. To fulfill the city’s affordable housing requirement, Lendlease partnered with Winn Development and the Boston Housing Authority to enable the development of 22 deeply affordable rental units and 30 mixed-income condominiums on an adjacent site, 14 of which are affordable. Previously, the neighboring site had been home to only 20 units that were greatly in need of repair. By redeveloping the Boston Housing Authority site, Lendlease surpassed the city’s affordable housing requirement and created a win/win for the neighborhood.
Clippership Wharf is best known for its innovative approach to safeguarding against sea-level rise and urban flooding. A variety of unique elements advance resilience on the site while adding green space and waterfront access in East Boston. Shoreline mitigation measures include a raised ground plane, stabilization of existing seawalls, new wetland resource areas, rain gardens and bioswales, as well as the update of neighborhood stormwater infrastructure.
In addition to raising the ground plane, Lendlease incorporated a first-of-its-kind living shoreline that celebrates the tidal fluctuations of the site and buffers the site against sea-level rise and storm events, absorbing and dissipating wave energy. The project achieved Leadership in Energy and Environmental Design (LEED) v4 Silver certification for Neighborhood Development, and has received national awards and recognition for its innovative and resilient design.
INNOVATIVE FEATURES/MITIGATION TECHNIQUES
Elevated ground plane. Lendlease set entrances to the residential units 14 feet (4.3 m) above mean high tide, well beyond guidelines from the Federal Emergency Management Agency (FEMA). Whereas FEMA uses analyses of past flooding events to dictate building guidelines, Lendlease wanted Clippership Wharf to be forward looking in its design and operations, knowing that storms are increasing in severity and becoming less predictable with climate change. In addition, raising the site to a higher elevation achieved remediation goals by reducing the amount of contaminated soil that needed to be excavated and removed.
Living shoreline. A living shoreline naturally buffers the project from changing tides instead of using seawalls and other fortifications to hold the water back from building structures. The shoreline features a series of salt marsh terraces that dissipate waves during storm surges. Repurposed granite blocks from the site’s previous uses were used to create the terraces, which provide habitat for repatriating native species in the intertidal zone. Boston Harbor’s daily 10-foot (3 m) tidal fluctuation causes a dramatic transformation of the site throughout the day, with the water as little as 12 feet (3.6 m) from the edge of buildings at high tide.
“It’s the first time in modern city history that a project on the harbor has created an intertidal zone with the pure intention of celebrating the tidal fluctuations with the plant communities and the wildlife habitat that it brings,” says Rob Adams, principal landscape architect at Halvorson Design.
Green space and public access. Anchored by a publicly accessible central courtyard, the property features significant green and open space with native plantings that absorb rainfall to reduce the risk of flooding on site and to neighboring properties. Green infrastructure includes rain gardens and a groundwater recharge system to capture and improve the quality of stormwater runoff. The site’s open space not only mitigates flood risk, but also incorporates amenities—such as a large amphitheater, a dog park, and docks—that the community is invited to enjoy.
Redundancy in building systems. An important element of Lendlease’s resilience strategy for the project was to have redundancy in various building systems. Instead of having a central plant, the site has multiple air-handling units to allow for continued operations in the event of an emergency in which building segments might be damaged.
Renewable energy. Solar panels on the roof ensure grid resilience and support a transition to renewable energy sources. The solar panels generated 200 megawatt-hours in the first year of operation, which is enough energy to power 25 to 50 homes annually.
Soft mitigation strategies. In addition to investing in what Lendlease referred to as “hard” mitigation strategies, like elevating the ground plane, the company incorporates “soft” mitigation measures into the project, which focus on the day-to-day operations of the facilities. The soft mitigation elements include deployable flood barriers to protect low-lying areas as well as clear instructions for staff in case of an emergency, safe egress routes, and methods for accessing important supplies. The combination of hard and soft mitigation techniques has been so successful that Lendlease has incorporated similar strategies into other waterfront projects the company is developing.
BUSINESS OUTCOME
Clippership Wharf has been successful in terms of resilience paybacks, high tenant demand, and industry recognition. The development has:
Avoided losses and damages. As a result of its resilient features and living shoreline, Clippership Wharf has created value by avoiding up to an estimated $2 million in claims per major storm event. As the frequency of storm events increases, Lendlease’s initial investment will pay itself off within a relatively short time frame.
Benefited from high demand. Demand at Clippership Wharf has been strong: the development was 96 percent leased less than a year after it opened, with the first 80 condo units selling in just eight weeks prior to the development’s full opening.
Achieved high return on investment (ROI): Rents reflected a 5 to 10 percent premium due to the desirability of the resilience and sustainability features.
Received national recognition and awards, including the following:
2021 New England Project of the Year by the Engineering News-Record;
2020 Climate Change Project of the Year by the Environmental Business Council of New England;
2021 Design Merit Award from the Boston Society of Landscape Architects; and
2020 Excellence on the Waterfront Award from the Waterfront Center.
In addition to its impressive financial performance, Clippership has delivered significant benefit to the East Boston community. The development enabled public waterfront access in the area for the first time in more than 30 years. From the project’s earliest conception, Lendlease wanted to create a waterfront experience around real access and inclusion that knit the community together, rather than hiding the harbor behind bollards and chains. Public sculptures and artwork by local artists are featured prominently throughout site, creating a welcoming and inclusive public realm.
LESSONS LEARNED
The development process was not without its challenges. At the time, the regulatory environment was not set up to approve the higher ground plane or the living shoreline concept. Initially, local agencies were skeptical and thought that the higher elevation of the site would block public access and limit integration with the broader neighborhood. In response, Lendlease redesigned internal roadways, ramps, and stairs to prioritize pedestrian pathways to and through the site, preserving water views and expanding public access.
The Lendlease team patiently worked through many regulatory obstacles to realize their aspirations for the site. Now, Clippership Wharf is held up as a prime example of resilient waterfront design, and the same agencies that initially pushed back are asking other waterfront developers to model their projects off Clippership. “The lasting legacy of the project will be how it pushed the dialogue around resilience in Boston,” says Nick Iselin, executive general manager at Lendlease Americas.
Lendlease has incorporated lessons learned during the development of Clippership Wharf into its other waterfront projects, like 1 Java Street in Brooklyn, New York. While the living shoreline at Clippership has been great at bracketing the tides, the way in which the ecosystem has evolved was not entirely predictable. “We’ve learned a lot about what it takes to get various species of salt marsh to take hold and propagate, for instance,” says Sara Neff, head of sustainability at Lendlease Americas, “and we’re taking these lessons and applying them to our other projects to ensure the health of shoreline ecosystems in addition to the protection of residents and our projects.”
Choosing to integrate resilience and sustainability into Clippership Wharf extends beyond providing a financial ROI to the development and ownership teams. The waterfront access, native plantings, and green space provide community benefit to the residents and surrounding neighborhoods. “We wanted to create a waterfront experience that looked and felt different from any other one in Boston,” Iselin says. “We wanted to create a unique public space that invites people to participate.”
“Clippership Wharf has been one of those projects that continues to evolve, and our own personal experiences are evolving with it,” says principal landscape architect Rob Adams. “On a grander scale, Clippership Wharf is just one piece of land along an entire coastline, but it has been inspiring to see how a single project has brought about so much change.”
ULI is grateful for the support of The JPB Foundation.
From the outset of project planning, Chicago-based development firms Campbell Coyle and Ranquist Development Group knew they wanted District House to be a catalyst for resilient and environmentally responsible design in the village of Oak Park. They teamed up with Omni Ecosystems, a Chicago-based firm specializing in living infrastructure nationwide, to incorporate private lawn terraces for select units on the second floor and a rooftop space featuring a native wildflower meadow to enhance stormwater management, reduce the urban heat island effect, and increase biodiversity.
Located in the Hemingway District of Oak Park on the commercial corridor of Lake Street, District House is a Leadership in Energy and Environmental Design (LEED) Gold–certified, 75,000-square-foot mixed-use building with 28 three-bedroom condominium units. It is situated in a walkable and transit-rich neighborhood that connects the surrounding area with the urban fabric of Chicago.
Oak Park is home to Prairie School–style design that is intended to reflect and celebrate the surrounding environment. The project team paid close attention to this rich history and sought to uphold the area’s architectural heritage with the development of District House. “We saw an opportunity to connect modern design with the important lineage of this place,” says Chris Dillion, president of Campbell Coyle. Studying the demographic trends of the broader metropolitan region, the team identified the building’s location as a prime opportunity to bring multifamily housing to a neighborhood well positioned for empty nesters looking to downsize and families hoping to move to the suburbs while not compromising on access to amenities like public parks and transportation.
In Greater Chicago, heavy precipitation and inland storms can lead to urban flooding and combined sewer overflow. In response to this growing issue, which is compounded by climate change, the Metropolitan Water Reclamation District of Greater Chicago (MWRD), within which Oak Park is located, has taken measures to revamp outdated sewage systems and implement gray infrastructure to help their communities better adapt to more frequent and intense precipitation events.
District House’s project team saw this as an area where they could exemplify their commitment to minimizing environmental impacts while strengthening sustainable design. While the MWRD did not require a certain threshold of stormwater management because the site is under a half-acre, the project team felt that it was important to go beyond and comply with the village of Oak Park’s requirement to serve 100 percent of stormwater on site. In Dillion’s words, “We saw partnering with Omni Ecosystems on their Green Roof product not just as a functional move from a resilience standpoint, but also to turn it into an amenity that would enhance the value of the residential units.” According to stormwater management tracking conducted by Omni Ecosystems, the lawned terrace spaces on the building’s second floor totaling 4,326 square feet have a retention capacity of 8,251 gallons of stormwater.
Omni Ecosystems was involved early on to provide technical support on how their green roof system could fit into the landscape architect and ownership team’s broader vision for the project. Above all, they wanted to make sure their efforts would align with the project’s overall design and budget goals, as well as being able to meet LEED requirements. Molly Meyer, founder and CEO of Omni Ecosystems, explains, “We sought to improve the nature of someone’s new home and to extend the usable outdoor space,” recognizing the important co-benefits offered by green spaces when it comes to human health, well-being, and stormwater management.
Climate Resilience Strategies
Green infrastructure – The private lawn terraces on select second-floor units and the shared rooftop space, which includes a native wildflower meadow ecosystem, help manage stormwater on site and create a cooling effect that reduces the urban heat island effect. The rooftop space totaling 11,083 square feet has a stormwater retention capacity of 21,140 gallons.
Extending the building’s life cycle – District House’s green roof helps add a layer of protection since roofs tend to degrade over time because of ultraviolet radiation and exposure to extreme temperatures.
Passive design – Deep floor overhangs provide weather protection for the building’s floor-to-ceiling window walls, and green infrastructure offers additional thermal insulation, both of which help reduce solar heat gain during the summer months.
Value Proposition
To understand the value created by implementing green infrastructure on select second-floor units, Campbell Coyle and Omni Ecosystems conducted an analysis comparing units on the second floor with lawn terraces to those on the third floor without. Despite a cost allocation of $20,000 for the green roof areas attributable to units with terraces, these units sold for an average of $95,030 more per unit. This analysis also does not account for the conventional wisdom that units typically increase in value on higher floors. The unique attributes of these terrace units became a prominent feature in the building’s marketing, “contributing to sales velocity that resulted in the project selling out as construction was completed,” Dillion says.
The tangibility of Omni Ecosystems’ living infrastructure resonated deeply with the project team. “When you are walking down Lake Street, you can see the meadow plantings which can be several feet tall. It is remarkable what it can do not only to address runoff, but it’s also beautiful and it contributes to the environmental expression of the building,” says Brian Court, partner with Miller Hull. This defining characteristic provided the building with an edge, especially for prospective buyers seeking amenities that generate aesthetic value and can be used and enjoyed at the same time.
Choosing to integrate green infrastructure into District House extends beyond providing a financial ROI to the development and ownership teams. The aforementioned wildflower meadow on the rooftop also boosts the ecological biodiversity of the area. In addition, a portion of the rooftop serves as a communal space for District House residents. “The focus on the rooftop system was on biodiversity, with a very lush wildflower meadow that has native plants and a lot of flowering perennials and annuals,” says Meyer, thereby creating a habitat for local species, some of which were thought to be long gone from the region.
Lessons Learned
Maintaining these spaces can prove challenging. Meyer describes an opportunity to continually improve upon practices for ongoing use and care. While Omni Ecosystems serves projects throughout the United States, some locally based projects like District House serve as a learning lab because Omni Ecosystems is requested to help provide guidance and physical maintenance knowledge. “We have a small but mighty in-house stewardship team who works locally, which is incredibly helpful because having boots on the ground informs the educational tools we create for the contractors who are certified to build and maintain Omni green roofs across the country,” she says. This component cannot be neglected because long-term stewardship of these systems requires careful attention to help maintain their ecological integrity.
The team’s intentional decision to connect the building’s green infrastructural elements to user experience meant “spending marginally a bit more while leveraging an innovative team to create an incredible amenity,” Dillion remarks. From District House’s clear show of leadership, Campbell Coyle and Ranquist Development Group incorporate similar goals and the same green roof system at other projects in the Chicago area. Simply put, Dillion emphasizes that the project process and development behind District House affirm that “there is an ROI on good design.”
Bagby Street, originally a four-lane throughway, is located in a tax increment reinvestment zone in Midtown Houston, a central neighborhood just south of the downtown core that has experienced significant growth since the early 2010s.
With that growth and increased demand on public infrastructure and utilities, the Bagby Street corridor was in need of major repairs and upgrades, especially to its stormwater infrastructure. “We saw it as an opportunity,” says Marlon Marshall, director of engineering and construction for the Midtown Redevelopment Authority (MRA), “to develop a sustainable capital improvement project to try to induce additional development in this area.”
Mitigating the urban heat island to ensure pedestrian comfort was a central design strategy; hot temperatures in Houston are a concern from May to October. The project team, led by Walter P Moore, also wanted to improve stormwater management to be prepared for Houston’s occasional heavy rains and hurricanes.
Before the reconstruction, 10 of Bagby Street’s 13 sidewalk blocks were in disrepair, and commuters used it primarily as a cut-through to reach two nearby highways. In addition, Bagby Street required significant drainage and utility updates, and averaged a summer surface temperature of 108°F.
Bagby Street has been reconstructed to provide more public space, attract development, and remain comfortable, walkable, and usable during times of extreme heat and flooding.
Extreme Heat Resilience Strategies
To meet the Midtown Redevelopment Authority’s goals, Walter P Moore and landscape architect and urban planning firm Design Workshop proposed reducing Bagby Street from four lanes to two, incorporating pedestrian safety features and adding significant green infrastructure. “We were able to improve levels of service even though we reduced the number of lanes,” explains Edwin Friedrichs, senior principal at Walter P Moore, “because with two lanes, it was much faster to walk across the street. We could give more through time on the roadway.” Less traffic also meant less waste heat production from cars idling at traffic signals or in traffic.
With reduced traffic delays and car idling, there is reduced emissions and waste heat.—Jennifer Peek, Executive Director, Infrastructure Group at Walter P Moore
Downsizing the road also allowed for a 38 percent increase in seating and social gathering space, which has contributed to “increased pedestrian activity,” says Marshall. To support the increased pedestrian traffic, the project team used heat-resistant paving materials and landscaping to maintain a comfortable environment. The team selected pavers with a high solar reflectance value and 25 percent recycled material content. “The pavers cost about double what concrete would generally cost,” says Alex Ramirez, associate at Design Workshop, “but they contribute to the branding and identity the Midtown District desired.”
The team also deliberately decided against brick pavers to minimize erosion and maintenance costs. According to Friedrichs: “We are experiencing more rainfall events with four to six inches of precipitation in just a few hours. That running water washes the sand out of brick pavers, which then need to be repaired.”
We put Bagby Street on a ‘road diet’ and gave a bunch of space back to the public.—Alex Ramirez, Associate, Design Workshop
The extra social space allowed the addition of 175 new, large shade trees along the corridor, which would also reduce temperatures and improve the pedestrian environment. The redesign also included rain gardens with heat- and drought-tolerant plant species and aligned new permanent irrigation infrastructure with a small park adjacent to the street.
When some property owners along Bagby Street initially opposed the removal of short, non-native tree species to make way for larger, native trees, the project team led a significant and successful community engagement effort. “We held meetings with every property owner to show what was going on through construction, what the completed project would look like next to their property, and to explain the benefits of low-impact development and trees,” says Friedrichs.
Outcome
The corridor’s new design has significantly improved local business, the pedestrian experience, and environmental outcomes, earning its place as the first Greenroads-certified project in Texas and the highest-scoring Greenroads project for several years until 2017, when the Sellwood Bridge in Oregon surpassed Bagby Street by one point in the rating system.
Bagby Street has also received recognition from the American Society of Landscape Architects, the American Council of Engineering Companies, and the Congress for the New Urbanism. One lesson learned from the certifications and awards processes is to document all the activities related to the rating system in order to achieve full credit, advises Jennifer Peek, executive director of the infrastructure group at Walter P Moore.
Moreover, “we’ve shown that green infrastructure can be beneficial from a dollars-and-cents standpoint,” says Marshall. In the first year after the reconstruction, nearly $30 million in private development was invested along Bagby Street. Property values along the street have increased 25 percent and 20 percent for the rental market. “Abandoned parcels were redeveloped into bars and restaurants,” says Ramirez.
Bagby Street has become a significant node of attractive establishments. It’s been very successful over the last four to five years.—Marlon Marshall, Director of Engineering and Construction, Midtown Redevelopment Authority
MRA and its partner organization, Midtown Management District, responsible for operations and maintenance, have also realized cost savings and work efficiencies from the redesign. By aligning Bagby’s irrigation infrastructure with the nearby park, for example, Midtown has seen a steady 10 percent water bill reduction every year since the reconstruction.
In addition to installing new heat-mitigation features and additional stormwater infrastructure, the project team and MRA coordinated with the local utility providers to replace overhead utilities on taller poles and consolidate poles on one side of the street. Those changes eliminate half the street’s overhead powerline conflicts with the big shade trees and allow the trees on the side of the street with utility lines to grow larger before needing to be trimmed, thereby reducing maintenance costs.
“Bagby has become a model project,” says Marshall. “We’ve had national visitors and presented it at many conferences as a prototype of tackling a number of aspects, including human comfort from a heat perspective.”
Design Workshop used a heat gun to measure surface temperatures at the street level; “there’s about a 20-degree Fahrenheit difference between areas where the direct sunlight is hitting pavement to pavement in the shade,” says Ramirez. The new design achieved a 42 percent increase in shade on sidewalks, allowing 90 percent total shade coverage and a 14 percent reduction in surface temperatures throughout the corridor.
The green infrastructure is also an asset during times of heavy rains and hurricanes. Since completion, Bagby has weathered three major floods, including Hurricane Harvey (2017). “While many other areas of Midtown Houston flooded,” says Marshall, “there was no flooding on Bagby Street during any of those major flood events. We’re proud of how Bagby performed.”
The design of the plaza was driven primarily by programming; even when it was parking, events were held there year-round. A key concern was the comfort and experience of the occupants. According to landscape architect Michael Vergason, “Summer heat was part of the discussion from the first conversations.”
We thought of it in terms of ‘how do we make this a comfortable space for people to gather in before, during, and after their experience downtown?’ –Johnny Campbell, CEO, Sundance Square
The goal was to develop an effective, comfortable space that would allow expanded programming but would also be architecturally beautiful.
Extreme Heat Resilience Strategies
The plaza’s most noticeable heat-mitigation feature is its four 86-foot mechanically operable shade umbrellas. Imported from Germany, the umbrellas provide almost 5,800 square feet of shaded space, are illuminated at night by multicolored LED lamps, and can easily be closed on cooler days when the warmth of the sun is welcome. Cedar elm trees provide additional shade along the sidewalks.
There are also two water features in the plaza—a large fountain and a water wall—that provide tangible and psychological cooling. Terraces around the park not only are comfortable places to sit but also effectively provide eddies for draining and funneling water toward the vegetation. Red-brick pavers match the nearby roadways and have a higher solar reflective index than the previous black asphalt.
I have never seen a shopping center make such a jump in sales at that age and at that level of maturity. It’s been four years of double-digit growth. –Johnny Campbell, CEO, Sundance Square
Outcome
According to Sundance Square CEO, Johnny Campbell, the plaza was an excellent investment “in terms of driving vibrancy, creating foot traffic and making sales happen.” The number of people attending events increased on average by more than 10 times, and retail sales in the vicinity jumped over 20 percent after the plaza opened. The per square foot sales price of downtown residential units also jumped 5 percent in the six months after the plaza’s opening.
The plaza has also demonstrably changed people’s opinions of and experiences in downtown Fort Worth; it’s not uncommon to hear “I’ll meet you under the umbrellas.” “The city is now seen to have a center,” explains Vergason; “it has become a destination.”
SkySong is a partnership between Arizona State University Foundation, the city of Scottsdale, and Plaza Companies, as master developer. Plaza Companies and Holualoa Companies are partners on the office buildings. The center is a hub for academic and private entrepreneurship that has revived the previously declining McDowell Corridor neighborhood. Before the center’s construction, surrounding companies were relocating and property values decreasing. SkySong itself is on the site of Los Arcos Mall that had been sitting vacant since the mid-1990s.
The center includes five class A four- and six-story office buildings, built between 2008 and 2019, 325 luxury rental apartments, a 157-bed hotel, retail shops, and several restaurants supported by an on-site urban garden. SkySong totals about 1.2 million square feet of commercial office.
The center’s sustainable design and extreme heat management features address local climate extremes, demonstrate Arizona State University (ASU)’s renowned built environment programs and initiatives, and are integral to SkySong’s ability to attract and retain innovative tenants. “The goal,” says Sharon Harper, president, CEO, and cofounder of Plaza Companies, “was to create healthy buildings and healthy environments that would set SkySong apart.”
We started with understanding our climate and understanding the new way that people and companies are spending their days. We are tremendously successful because of that sensitivity. –Sharon Harper, President, CEO, and Cofounder, Plaza Companies
Extreme Heat Resilience Strategies
Organized in four quadrants around an iconic, 150-foot-tall shade structure covering a central plaza, SkySong’s buildings are near one another, thus allowing the structures themselves to provide shade to neighboring buildings as well as the pedestrian circulation points around the site. The buildings are oriented to minimize solar heat gain and incorporate multiple facade improvements, including horizontal and vertical shade screens, high-performance window glazing, and small windows on the west and east-facing sides.
Each building capitalizes on the north face with “windows to innovation” where clearer glass components allow additional natural light and views while vertical shade elements prevent glaring sun during parts of the day and year when solar angles reach that face of the building. SkySong buildings 3 and 4 use a standard metal lath in a favorable solar orientation such that the shape of the punch in the panel provides transparency at lower viewing angles and opaqueness at the higher sun angles.
The site layout facilitates efficient pedestrian travel between indoor, air-conditioned lobbies and comfortable and engaging outdoor spaces. Buildings share centralized parking to minimize outside travel time, and pedestrian pathways are well shaded by vegetation, built structures, or both. The centrally located custom 50,000-square-foot shade structure consists of eight conical-shaped pieces covered with tensile fabric supported by eight, 111-foot-long steel legs. Indoor bike parking, showers, and connections to two nearby parks encourage non-motorized travel.
Developer Sharon Harper also notes that “the efficient operation of the buildings is a key component for investors and tenants and for managing temperature.” SkySong has LED lighting as well as daylight harvesting and motion sensors to minimize lighting use. All cooling equipment has nighttime setbacks when buildings are less occupied and staggered start times to minimize peak electric demand. Similarly, SkySong’s construction was largely completed early in the morning and partially at night to protect workers’ health and ensure daytime heat exposure would not reduce the quality of building materials.
SkySong is architecturally appealing with functional components for managing heat. –Korey Wilkes, Principal, Butler Design Group
Outcome
Achieving the objective of revitalizing the McDowell Corridor neighborhood and spurring innovation, SkySong has generated over $588 million in local economic output with a projected regional output of $32.17 billion by 2046. “The economic output is phenomenal,” says Harper. SkySong draws over 5,500 visitors each month and houses 57 companies.
The first two commercial buildings are over 90 percent leased, the more recent SkySong 3 and 4 are 100 percent leased, and the new SkySong 5 is nearly 80 pre-leased. Prominent tenants include multiple enterprising cloud computing firms such as Oracle, photography and imaging equipment supplier Canon, CenturyLink Communications, TicketMaster, Groupon, a research and development subsidiary of Bridgestone Tires, and companies in accelerator programs run by ASU’s Office of Entrepreneurship and Innovation. Many of SkySong’s early tenants have experienced significant growth and relocated to larger office spaces within the development.
SkySong’s buildings are all LEED Silver certified and have achieved Energy Star certification. The heat-conscious landscaping and design creates outdoor amenity spaces that are enjoyed year-round. “Even when it’s 115 degrees,” says Harper, “there are people sitting in the shade, connected and social.
Adopted in 2011, Harris County’s Low Impact Development and Green Infrastructure (LID/GI) Design Criteria provide detailed guidelines and requirements that enable real estate development projects using LID/GI techniques to obtain development permits in the unincorporated portions of the county. Stonebrook Estates was among the first in the Houston area to implement LID principles.
Stonebrook Estates developer Terra Visions LLC could have managed drainage on the site by using a six- to seven-acre detention pond, but instead chose to pursue the LID techniques as part of the overall amenity offering for the development. The development entry features a green, landscaped drainage corridor designed to serve as a gateway to the homes. LID features also provide residents with more green space, a trail system, and a water feature that naturally guides stormwater to two 50-foot-wide detention channels that then filter the flows to an interior detention basin. The basin manages the release of water at a rate and quality that is safe for the surrounding environment.
Innovative Water Management Features
Natural drainage system. The natural drainage system at Stonebrook mimics the natural flow of water across a green landscape, directing stormwater into linear and lake-style detention basins; from there, stormwater is slowly released to nearby channels and bayous.
Engineered soils. The first inch of stormwater runoff from the development is routed through engineered soil filters that remove pollutants from the runoff and ensure that the development complies with local post construction stormwater quality management regulations. The engineered soil filters (known as biofiltration) are designed to provide a very high filtration rate, thus avoiding surface ponding.
Curb cuts and false-back inlets. Roadways are sloped and use “false-back inlets” on the curbs to drain stormwater into bioswales instead of traditional precast concrete storm sewer pipes.
Value Proposition
Randy Jones, Terra Visions LLC principal, describes the LID features as a key part of the development’s sense of place. After Houston’s 2014 downturn caused by falling oil prices, the developer worried the homes would be priced too high for the market. However, although sales volume and absorption were initially lower, the development fared well, with average home prices about 25 percent higher than expected. Jones describes the community as a “complete blend” that was attractive to the suburban Houston market. “It’s on a private street, a gated neighborhood, and well landscaped with LID components right at the front door. When you put all the pieces together, the market likes it,” he explains.
“We could have put a six- to seven-acre detention pond on the far side of the development and gone off without thinking about using the drainage system as an amenity. But the idea was to be different. We chose to use the facility as landscaping and give it a look that’s not an ugly ditch.” Randy Jones, Principal, Terra Visions LLC
The site engineer, Michael Bloom with R.G. Miller Engineers, estimates that the natural drainage system, which is used only in a portion of the development, reduced the site detention requirement by 24 percent, which increased lot yield.
Stonebrook’s natural drainage system was put to the test during the Tax Day Flood of April 2016. Stonebrook received approximately 12 inches of rainfall in a 24-hour period, which is about equal to the 100-year rainfall for the area. The stormwater management system at Stonebrook “functioned better than anticipated given the rain storm intensity,” says Jones. “I was absolutely amazed that the stormwater stayed in the system and didn’t flow into the streets or yards.” The natural drainage system was able to capture then convey the rainfall and runoff, and both the linear and lake-style detention basins successfully released the design flow to the nearby channels and bayous.
Lessons Learned
A low-impact development framework presents an opportunity to fulfill market demand for environmentally friendly communities. LID principles inherently include natural amenities that are attractive to homeowners, such as trail systems and open space. Jones described green infrastructure as a key component of a well-rounded community desirable to home buyers.
Natural drainage systems can cut costs of drainage facilities. Stonebrook Estates’ drainage corridor is part of the landscape of the community—and is a more cost-effective alternative for the community’s utilities, given the limited access to the drainage piping system.
Green infrastructure can mitigate risk and avoid losses. Stonebrook Estates has already survived a major storm, the Tax Day Flood. Infrastructure in this community has proven to be resilient and protected its community members.
Denver Water headquarters’ blackwater is treated on site through various closed and open aerobic tanks, a constructed wetland, as shown in the photo, and a final filtration process before reuse. (Frank Ooms Photography)
