A Pocket Full of Stormwater
Integrated resource management puts stormwater on the balance sheet.
Turning his attention to municipal watershed ecology, a leading aquatic ecologist and urban geographer says that in a healthy natural ecosystem every resource gets recycled in perpetuity, through every level of the food chain, from the bottom to the top and back again. And, he says, sustainable cities would function the same way.
The infrastructure of such a city would generate revenues rather than expenses; it could even turn a profit.
According to Patrick Lucey, who is the founder and senior aquatic ecologist for Aqua-Tex Scientific Consulting Ltd., sustainability can be achieved in the near future by redesigning urban ecology to capitalize on the byproducts of urban living in a closed-loop system.
Although he says no such cities exist today, all of the components needed to create these living spaces do, and many have been employed for years, only not in a configuration that would promote sustainability.
Lucey says, however, it’s not something we can achieve by sticking with the old plans. And by that, he means very old plans.
One Kind of City
Worldwide, Lucey says, “There is only one kind of city. And it’s based on a 2,000-year-old Roman design.” The Roman infrastructure “paradigm” comprises centralized waterworks, graded roads optimized for speedy drainage, and centralized waste disposal. The problem is that since Roman times, in spite of our vastly different circumstances and rapidly diminishing store of resources, “we haven’t ever stopped to take apart the cities and decide if there’s another way to design them.”
Lucey, who has served as a special advisor on water policy to the British Columbia government, asks, “Is there another way to design municipal infrastructure for water transport and to manage the ecology?”
It’s a looming question under current economic conditions. The Congressional Research Service estimates that the United States will need to invest somewhere between $400 billion and $1.2 trillion in the next 20 years to repair, maintain, and upgrade its water infrastructure alone, not to mention the repairs that will be needed to transportation networks, energy, pipelines, and other major infrastructure.
|Photo: Charles River Watershed Association
Artist conception upon completion of the upgrade. (Note: In the final design the town opted not to deploy porous pavers as shown in this depiction.)
Anthony Sease, director of business development for Natural Systems Utilities, says he cannot imagine any “foreseeable path” to finance that undertaking, unless we come up with a radically different way of doing things.
“Water could be the new oil,” says Sease. However, by combining an array of existing technologies such as distributed small-scale treatment plants, rainwater harvesting and reuse practices, and ecological treatment systems that utilize or mimic nature, he believes it should be possible to realize 60% reductions in potable water demand. And he says that by banking the significant savings in energy costs for conveyance and treatment, an integrated water management system focused on sustainability “would pay for itself in four to five years.”
Noting economic difficulties of the current decade, population growth trends, and resource depletion in the United States and abroad, Lucey says that within a few years, regardless of what policy we adopt, necessity will drive a transformation in how we build and run our cities. But that time may be running short to avoid a crisis.
To that end, Lucey proposes moving toward a decentralized, disaggregated closed-loop design paradigm for cities that is based on “how cities function rather than how they are structured.” He says it’s time to transition “from environmental engineering to engineered ecology.”
But he emphasizes that in order to be truly sustainable, the infrastructure behind these cities will need to satisfy three requirements: it must be economically productive, environmentally neutral, and socially responsible. He calls these criteria the triple bottom line, and he says these values are at the core of the integrated resource management (IRM) concept.
IRM promotes not only the reuse of materials, but also capitalizing on any incidental attributes of those materials that might be useful for any particular purpose. For instance, recent projects have demonstrated that useful thermal energy for building heating can be harvested from the natural biological heat generated within sewage as it flows through sewer pipes before it even reaches the treatment facility.
With these and similar types of approaches, Lucey says, infrastructure can “become revenue generating rather than tax draining.”
Karen Sands, sustainability manager for the Milwaukee Metropolitan Sewerage District (MMSD), is an advocate of the IRM approach. As a leader of one of the most innovative sustainable urbanism initiatives in the United States, she says, “We didn’t always call it IRM, but we’ve been doing it for a while. For our flood management projects we strive to contain the 1% probability flood, but also to provide neighborhood amenities like walking paths, aesthetics, things that would raise property values in general—to help to lift the neighborhood up, in addition to meeting our primary goal, which is eliminating flooding.”
MMSD serves 28 municipalities in the Milwaukee area. The agency hopes to augment its aging combined sewer system near the city’s center with green practices to prevent overflows, while it employs naturalistic bioinfiltration and biorentention practices to ease the demands on stormwater systems in the suburban districts it serves.
Addressing stormwater overflows in an economical fashion while promoting ecological restoration requires carefully balancing gray infrastructure with the appropriate green infrastructure.
“We have a project in Shorewood [WI], an inside ring suburb, where we avoided upsizing a pipe and instead put rain gardens in peoples’ front yards and disconnected roof drains from the combined sewer system and ran them into the rain gardens,” says Sands. She adds that the project saved, “the cost of a really major infrastructure project.”
For another of MMSD’s greening initiatives, Sands says, the agency invested $5 million in a green roof partnership program to support the construction of five additional acres of green roofs in Milwaukee. “That not only helped us manage stormwater, but it can double or triple the lifespan of the roof by protecting it from UV [ultraviolet] rays,” she notes. “It provides insulation so your heating and cooling cost go down, and it’s a great aesthetic amenity, if people have visual access to it.”
Sands says the benefits of this kind of green infrastructure go far beyond those that can be tallied on a balance sheet. She explains, “Two of our 14 awards went to hospitals; patient healing times actually go down when patients can view a green roof.
“The point of all this is to reduce basement backups and sanitary sewer overflows, but if we communicate with someone, and they want to talk about property value impacts or air-quality impacts, I am happy to do that, because there are so many benefits to green infrastructure.”
Natural Byway Meets Information Highway
The agency has also implemented a program to allow nature the opportunity to do some of its own housekeeping. MMSD’s award-winning Greenseams program, in operation since 2001, makes voluntary purchases of open space along waterways and undeveloped privately owned properties in areas expected to have major growth in the next 20 years.
By storing and infiltrating water into the ground naturally, the landscapes purchased by the program help prevent future flooding while supporting sustainable economic development. With more than 2,000 acres now under its stewardship, the program also helps support and protect MMSD’s structural flood management projects—infrastructure investments worth hundreds of millions of dollars.
To complement its innovative strategies to preserve and enhance the region’s natural green infrastructure and its upgrades to improve its gray infrastructure, Sands says, the agency is investing in a piece of information infrastructure.
“We’re developing a user application where people can go in and enter whatever they’ve got for green infrastructure—maybe a rain garden or a green roof—then the software will calculate all the benefit they receive from that, including their energy savings.” Release around Earth Day 2011, the Web-based application repackages calculations that were previously available as a worksheet developed by the Natural Resources Defense Council. Sands says she is looking forward to sharing the new, “slick user interface that is public-friendly.”
According to Kimberly Brewer, associate director for the engineering consulting firm Tetra Tech, the motivation for undertaking an IRM initiative can be as varied as the potential benefits. “Sometimes the motivation comes from the outside—really stringent regulations by the state or local government,” she notes. At other times, she says, the
motivation can be more internal, an outgrowth of “a set of values a community may want to move toward. Sometimes it’s a combination of the two.” But, Brewer says, “Environmental constraints, such as water scarcity, are probably the number-one driver so far.”
However, in at least one case in “water-rich” New England, the inspiration arose from circumstances that, on the surface, might appear somewhat less dire.
Little Joy in Blackstone
Kate Bowditch, director of projects for the Charles River Watershed Association in eastern Massachusetts, says, “We see stormwater as a very valuable resource. One of the things that we always emphasize in our advocacy and education work is that even in an area like New England, which has traditionally regarded itself as very water rich, we really can’t afford to be throwing away our stormwater runoff.”
In spite of the abundant 40 inches of rainfall the region averages each year, Bowditch says, “Our perspective is that a lot of the problems we have in the urban water environment, especially in a place like Boston that has a lot of older development, is that we developed all of these systems to get rid of water as fast as possible; we basically treat water like a waste product—it’s really a loss to our watersheds. We’re now seeing times of water scarcity and stress, especially in the summer, in rivers streams and tributaries.” Bowditch says the region is also beginning to see competition between ecological uses and water suppliers. “That’s an issue we need to tackle and figure out how to redesign our infrastructure system so that we don’t have those kinds of stresses.”
The town of Blackstone, MA, has begun to take some important first steps in the region in that direction. Bowditch says that, typical of a New England small town, Blackstone owes a lot more than just its name to the river that runs through its downtown. Townspeople recognize the importance of the river to the town’s heritage, arcing back centuries to an era when New England’s rivers served as transportation hubs and power sources for mills and industry.
Although folks in the area still treasure the Blackstone River, nowadays the town has a new passion. Blackstone, she says, “is a baseball-mad town.” Lately, however, a dry spell has been sapping a bit of the enjoyment from the game.
Bruce Wilson, Blackstone’s director of public works, says there is only one regulation-size ball field in town, and it’s the centerpiece of the community. Located on the grounds of the Blackstone Municipal Center, a complex housing town offices and essential civic services, the ball field is the go-to location for school sports programs and summer youth leagues, and it plays host to the town’s most important civic celebration, the annual carnival commemorating Memorial Day.
And it’s drying out.
The field, Wilson explains, lacks an irrigation system or any reliable source of water for the turf during the playing season. Things got particularly tough last summer when one of the wells that supplied potable water for the town “came apart,” says Wilson, forcing Blackstone to impose phase three water restrictions, placing a ban on all outdoor watering.
While the infield was being transformed into a trampled dustbowl hard as rock, a few feet away, runoff from the town’s municipal center roof and parking lots flowed freely into a small creek, carrying whatever sediments and pollutants it had picked up along the way, untreated, into the Blackstone River.
Behind the scenes, however, the Charles River Watershed Association and several interested citizens had been busy working out an arrangement with representatives of a local power plant that might restore hope for baseball in Blackstone.
According to Bowditch, although the power company, International Power America, employed a highly water-efficient dry cooling process at its gas-fired plant in town, it agreed to further mitigate the impact of its water use by contributing $250,000 to a water use mitigation fund governed by a panel of stakeholders that included representatives of the town of Blackstone.
“The goals of the fund are to promote improvement in water resource management with a particular focus on recharging groundwater and reducing water use,” explains Bowditch, “to offset the power plant’s water use.”
The agreement also specified that the funds be used to install the kinds of practices that could serve as demonstration projects with educational opportunities for residents of the region. The municipal center and denuded ball field presented the perfect opportunity.
“We selected the location because it’s the place where almost everyone in the town comes at some point in the year,” says Bowditch.
Wilson says the funds could help the town meet multiple goals, including added parking at the municipal center and engineering a safer traffic flow for police and fire department emergency vehicles that operate from the center.
The parking area redesign incorporates low-impact development (LID) stormwater practices that will capture and infiltrate runoff from the rooftop and parking areas of the site, reducing the flow of polluted stormwater runoff into the Blackstone River. In addition to removing pollutants and moderating peak flows, bioretention cells included in the plan will improve the aesthetic of the site. And two 10,000-gallon underground cisterns will be installed to collect roof runoff to irrigate the athletic fields.
The design calls for a long vegetated swale feeding a large bioinfiltration area at the back of the parking lot. “It will look like a big rain garden at the lowest point in the system,” says Bowditch. The entire system will be underdrained, and any overflows from the underdrain will be channeled into a swale and then to a tributary to flow into the Blackstone.
Although the cisterns themselves will be underground, Bowditch says, “We purposefully selected practices that are visible as opposed to a lot of underground structures. We’re going to use signage to make people aware of the fact that they are collecting runoff from the roof for reuse.”
She says an interesting discussion arose during the design phase: whether, in the instance of a six-week drought, drainage from the rooftop area alone could provide enough water to irrigate the whole infield. “We initially looked at taking any overflows from the biofiltration areas and putting that in the cistern as well to provide supplemental storage.” However, since the project represented such a broad departure from customary practice in the region, Bowditch says the town leaders preferred to take a more conservative approach to reuse. Although she says the literature supports the safety of reusing parking lot runoff for irrigation after it has passed through the level of biotreatment proposed for the site, in the end, “The idea of reusing runoff from a parking lot appeared not to be something the town selectmen would be comfortable with.”
In keeping with that conservative approach, she says, “The town feels it’s very important to ensure there is nothing other than roof runoff getting into those cisterns, so one of the next steps is some dye testing to make sure the drains are exactly what we think they are.”
However, Bowditch believes that as citizens in the region become familiar with ecologically oriented water management practices, communities will become more receptive to exploring aggressive reuse options. “We don’t have a lot of examples in New England of this kind of green infrastructure system,” she notes.
A New Ballgame
“Aggressive treatments are actually coming out of private sector developments rather than public sector projects,” says Bowditch. “Even in a case like this, where the project is being paid for with private funds, the town is still responsible for operations and maintenance, and that was a really significant issue for the town.” For example, although the town had initially considered implementing porous pavers to promote better infiltration in the parking area, it eventually decided against that option because of the operation and maintenance expenses involved, including the purchase of a vacuum street sweeper that would have been required to ensure the best performance.
With the design near completion during the winter of 2011, Bruce Wilson says, the plan had been “well thought out.”
“We had a lot of input from everywhere. A lot of it was making sure we had the proper traffic flow and parking requirements and still maintained the pretreatment that we were looking for. There was a good amount of effort on everyone’s part to get something that worked.”
Bowditch says Beals and Thomas Inc., an engineering firm with experience in LID projects in the Charles River watershed, made a considerable contribution to the design of the municipal center project. “It’s a rural area,” she says, “and there are no projects like this in that area. I think they saw a terrific opportunity to generate some interest.”
Wilson expects construction will begin late in the fall, after the close of this year’s baseball season. Next year, however, with cooperation from nature, a verdant, well-managed infield should give sports fans in Blackstone something to cheer about.
After shepherding the Blackstone Municipal Center project through the planning process, Bowditch expects to see “a lot more reuse in private developments—where their water costs are a significant factor in their decision making.”
“What I hope is that those projects will serve as a model, and, gradually, public projects will begin to move toward those technologies as well. There are a lot of larger cities that are starting to use these technologies successfully, and that’s when it’s easier for municipal officials to go ahead and move in that direction.”
Don’t Just Recycle—Reuse
Lucey observes that, in contrast with green certification initiatives, IRM projects can provide a direct route to revenue. Describing preliminary results of financial modeling exercises he generated using IRM concepts, Lucey says, “If we’re right, it’s far more profitable than anyone realizes.”
Working with a development team in Victoria, British Columbia (BC), Lucey helped conceptualize a project called Dockside Green that, when completed, earned a record-setting LEED Platinum rating superceded only by Olympic Village at Southeast False Creek, another project with which Lucey was involved. However, Lucey says awards are not the primary objective, but sustainability is, both economic and ecological.
Although the project was a mixed-use infill development planned for a brownfield site, Lucey says that with all it had going against it, at first glance there appeared to be no way that Dockside Green could be made profitable. However, an approach that argued for enlightened reuse pointed to a viable strategy.
For example, standard development practices would have required a substantial investment for site remediation alone. Lucey says that procedure would have entailed digging up and hauling off the debris left over from previous activities at the site for disposal in a landfill, with the associated expenses.
But breaking with tradition, the development team “took the Royal Institution of Chartered Surveyors valuation and applied it to the design process, integrating all of the components with the understanding that every design decision must increase the value of that development.”
Using that kind of process leads to the discovery that “Although it is cheaper to pave, if you restore the ecology you increase the value of the project,” he says.
The team reached the conclusion that it would be more profitable to treat debris at the site as a resource rather than an encumbrance. They collected the lightly contaminated material, contained it within sealed berms, and covered these to serve as the contours of a brand new landscape feature: a freshly constructed artificial mountain stream that today brings a touch of nature to the site. “It’s as if we dragged in a creek from the wilds of the Rocky Mountains and dropped in the middle of downtown,” says Lucey.
The stream, which has no headwaters but simply recirculates water collected from properties on the grounds of the complex, has become one of the most visually dramatic, revenue-enhancing features at the development. And according to Lucey, units that command a creek overlook also command premium prices, contributing significantly to the profit potential of the project.
And it circulates clean water. An onsite water treatment plant, scaled for the development, resides “right next to the most important bakery in the city.” The plant makes it possible to “completely recycle everything on site. It’s 100% rainwater capture, 100% reuse of all of the water from the treatment plant on the site. Any excess is discharged to the ocean, essentially at drinking water standards,” says Lucey.
A Canadian Word for Water
Restrictions on the availability of potable water inspired innovation on a separate project, Olympic Village at Southeast False Creek, BC.
“British Columbia has fully 10% of the earth’s liquid freshwater,” says Lucey, “so water is very inexpensive, along with electricity, with a very small population to serve.” However, to uphold the values of sustainable water use at the Olympic sites, the city of Vancouver passed a bylaw for the new Olympic Village at the Southeast False Creek that said no potable water could be used for irrigation “under any circumstance.”
The development strategy, however, contained plans to eventually market upscale residences at the complex to customers with the means to match their tastes. This posed a customer relations challenge. Lucey estimated that prices on of some of the units could run into the multimillion-dollar range. “You don’t tell somebody who just spent seven million dollars on their house they can’t water their plants,” he says.
To solve the dilemma, he says, “We captured all of the rainwater, then we made the argument that for every cubic meter we captured, we’d get to store an equivalent cubic meter in the city water supply up in the hills that doesn’t have a label on it.” At that point, he says, there would be “two types of water molecules coming into the site: one labeled ‘drinking water’, to which all the city bylaws applied, and the other labeled ‘water’, to which no bylaws applied. We used water we captured on the site, and we banked that water in the city reservoir,” making it possible for residents to water their gardens while maintaining compliance with the bylaw.
Model of Reuse
Lucey says modeling is the key to realizing the value that IRM can generate from the resources available at any potential site, whether they have been used only once or have been reprocessed for use any number of times. “You need to be able to track everything and document each highest and best use.”
He says has found the Proper Functioning Condition method, used by the National Forest Service and Bureau of Land Management and which he has “taken and applied to urban environments” to be one of the most powerful modeling methods available.
For Dockside Green, Lucey says, “When the loop was completely closed on water and energy, the site suddenly became profitable.”
But he notes that models do have their shortcomings. “We’ve worked out the economics, but we have not done so well on the social side. I have not found anyone to take on the social aspects in the models.”
However, he says the toughest question facing proponents of IRM today is not where one might discover opportunities for sustainable practices, but “How do you procure the kind of innovation we’re thinking about?”
He acknowledges that regulatory and “legacy of practice” barriers will likely act as a brake on widespread adoption of IRM in the short term, particularly in the United States, where he says a slow-moving and precautionary legal tradition holds considerable influence. But he says these very ideas are under serious consideration around the world, particularly in regions of Asia where communities face resource constraints much tougher than those we now face in North America.
Nonetheless, timeliness itself might make a compelling argument for implementing IRM to address our current difficulties. Lucey says, “The amazing thing is that it can all be done with current technology; the key is to organize that existing technology in new ways.”
Writer David C. Richardson is a frequent contributor to Forester publications.
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