Replace Houston McMansions and sprawl with what?

At least a few of the homes flooded in Houston are McMansions. For example, see this video of rescue efforts in one neighborhood where water is past the first floor of McMansions.

Once the waters recede, what will happen to these McMansions? Critics of such homes argue that they are often poorly built. Are they worth restoring and rebuilding or will homeowners pursue other options? What will communities approve and will they promote other options beyond big single-family homes?

Rarely do suburbs and big cities have opportunities to rethink past development decisions on a large scale. Houston is known for sprawl and a number of commentators (including me) have already suggested that such an approach often does not work well with flooding and water issues. Yet, overturning decades of sprawling suburban development is a difficult task and is likely even harder when residents just want to get back into their homes.

 

“People care about flooding…they don’t care about stormwater management”

An article discussing the difficulties of avoiding flooding in a sprawling city like Houston includes this summary of a key problem:

One problem is that people care about flooding, because it’s dramatic and catastrophic. They don’t care about stormwater management, which is where the real issue lies. Even if it takes weeks or months, after Harvey subsides, public interest will decay too. Debo notes that traffic policy is an easier urban planning problem for ordinary folk, because it happens every day.

It is difficult to get people interested in infrastructure that does not effect them daily or they do not see it. Yet, flooding is a regular issue in many cities and suburban areas and it can be very hard to remedy once development has already occurred. Indeed, it is difficult imagine abandoning full cities or major developments:

The hardest part of managing urban flooding is reconciling it with Americans’ insistence that they can and should be able to live, work, and play anywhere. Waterborne transit was a key driver of urban development, and it’s inevitable that cities have grown where flooding is prevalent. But there are some regions that just shouldn’t become cities.

Given the regularity of flooding in developed areas, it is interesting to consider that there are not more solutions available in the short-term. Portable and massive levees? Water gates that can be quickly installed? Superfast pumps that can remove water?

Flooding as a major suburban problem

Suburbs are often derided for their sprawling development that chew up acres of land and significantly alters more rural settings. Within that sprawl, one problem that consistently shows up but receives less attention than it should is flooding. For example, the significant rain received in parts of the Chicago region this past Wednesday (July 12) has impacted a number of suburbs:

While some suburban communities Saturday saw water levels begin to recede in the wake of Wednesday’s downpour, others still are bracing for the worst of the fallout from flood-ravaged rivers experts expect will crest later today into next week.

In Algonquin, the Fox River reached 11.79 feet by noon Saturday, with the National Weather Service predicting it will crest nearly a foot higher, at 12.9 feet, sometime Tuesday.

As of noon Saturday, The National Weather Service reported the Des Plaines River near Gurnee had reached a record-setting 11.96 feet and was expected to crest at about 12 feet sometime in the next 24 hours. In Lincolnshire, the level had dropped to 15.5 feet, but official predictions indicate the river may rise again to crest at 16.3 feet sometime Sunday.

While Wednesday’s rain was unusual (and we could argue about how frequently such big storms do and should occur), the results highlight a common issue across suburban landscapes: what happens to all that water? Suburbs don’t just change rural or farm land into developments; they change how water flows and is absorbed into the soil.

A variety of techniques are available to deal with the water. Common in this area are retention ponds, sunken areas within developments that are often dry but serve as places where water can pool when excessive rainfall occurs. In the Chicago area, the need to deal with flooding led to one of the largest civil engineering projects in the world: Deep Tunnel. Floodplains are fairly visible during heavy rains as homes and other structures near large bodies of water, particularly rivers, are affected. Less easy to see are  formerly swampy or marshy land which have been filled in, the channeling of creeks and rivers (or even covering them up completely), and covering the ground with less permeable surfaces such as roads and driveways (this can be combated by using different kinds of surfaces).

Instead of viewing flooding within major metropolitan regions as the unfortunate result of large storms, we should see it as a regular issue within suburban settings. And if we do so, that might prompt better plans to avoid the flooding that comes when so much land is altered.

Why Canadian communities may not have an incentive to avoid flood plains

If the costs for rebuilding in flood plains is covered by the provincial and national governments, why would communities limit building on those flood plains?

As the battle to protect homes from flooding continues across the country, questions are being asked about whether it’s time to reconsider regulations that allow developers to build on flood plains.

Jason Thistlethwaite, an assistant professor at the University of Waterloo’s faculty of environment, says the problem is that municipalities set zoning regulations and collect property tax revenue but do not pay for rebuilding costs after natural disasters.

“The municipality really doesn’t have an incentive to go in and use land-use planning and building codes and communications strategies to tell people that they are at risk of flooding, particularly given that most of the revenue comes from development, it comes from property taxes.” Thistlethwaite said. “So they face a real conflict of interest…

Last February, the Parliamentary Budget Office released a report estimating that over the next five years the federal government will dole out an estimated $902 million a year in disaster-related relief to provinces and territories.

I could see at least two good arguments against building in flood plains:

  1. The financial costs in the long run. Of course, the suggestion here is that local communities don’t bear the costs. But, even if they are paid at higher levels, the costs are going to get passed down eventually. Additionally, communities might benefit from property taxes but the reconstruction times and costs also would limit the property taxes they can collect.
  2. Environmental reasons: it can’t be good to have buildings and other debris from the built environment consistently washed into waterways. Limiting development on floodplains also allows for rivers and other waterways to go through natural cycles.

Either could be a good enough reason. However, as noted above, it is very difficult for communities to pass up on allowing development on desirable properties. There are similar situations in the United States.

One of the better options I’ve seen in some suburbs is to convert these flood areas to parks. This accomplishes two purposes: (1) when flooding does occur, the damage is reduced since it affects fewer buildings and (2) having a park nearby can enhance property values and the quality of life.

Solving flooding in China with “sponge cities”

Chinese officials are providing funds for “sponge cities” to reduce the effects of flooding:

“A sponge city is one that can hold, clean, and drain water in a natural way using an ecological approach,” says Yu, who is helping to coordinate the national project.

Traditionally, Chinese cities handled water well, Yu notes. “But in modern China, we have destroyed those natural systems of ponds, rivers, and wetlands, and replaced them with dams, levees, and tunnels, and now we are suffering from floods.”…

Reverse-engineering a city to make it more spongey requires a mental rather than physical shift, he argues. “It’s a whole new philosophy of dealing with water. It is about how we plan and design our cities in an ecological way. Not about piecemeal, manmade engineering projects. So we need to avoid this kind of trap.”

Sponge-city design could also run up against China’s centralized planning system.

It sounds like this is a major work in progress. As has been found in American cities, such as Chicago, trying to solve flooding issues after the city is a certain size is quite difficult. Are cities really willing to move residents or commercial structures to better deal with water issues? Is it only possible to make changes after a major flood convinces people? The optimal way to do this would be before the development happens as planners and others can set aside space or promote greener options.

“Touring the Deep Tunnel and Thornton Quarry,” one of the largest civil engineering projects in the world

Given the recent rain and flooding in the Chicago region, this seemed apropos: one journalist describes a recent tour of the Thornton Quarry and Deep Tunnel complex south of the city.

On Saturday, I joined the Southeast Environmental Task Force (SETF) on one of its tours of Chicago’s goliath infrastructure. The tour featured the future site of the Thornton Composite Reservoir, the largest such reservoir in the world, and a Deep Tunnel pumping station 350′ below ground at the Calumet Water Reclamation Plant. Both are part of the Metropolitan Water Reclamation District (MWRD)’s gargantuan Tunnel and Reservoir Plan, the multi-decade, multi-billion dollar project designed to protect the Chicago region from the flooding and pollution caused by overflowing sewer and stormwater infrastructure…

After this brief greeting, we drove to the former Thornton Quarry in the south suburban city of Thornton. The quarry, which is one of the largest aggregate quarries in the world, is still being actively mined nearby; however, the MWRD has acquired two significant portions of the area for the Deep Tunnel project. The resulting reservoir will hold 7.9 billion gallons of water, which MWRD Principal Civil Engineer Lou Storino estimated is the equivalent of 36 Soldier Fields. While on site, staff mentioned that we would be one of the last tours to descend to the base of the quarry, which will enter into operation shortly.

Tourists may find man-made sights like Hoover Dam impressive but Chicago area residents don’t have to go far to see similarly impressive projects. Not that the public could simply walk into the Deep Tunnel complex but you can glance at the quarry from the I-80/94 corridor. The Deep Tunnel project was quite costly and time-consuming but represents an effort to more effectively drain water away from Chicago, an on-going concern that even one of the largest civil engineering projects can’t solve on its own. This is what you get when you build a 9+ million metropolitan region centered on a swampy area near Lake Michigan…

Toronto park also serves as a dyke to protect surrounding neighborhood

One Toronto park goes beyond providing recreational space by providing protection against flooding:

Corktown Common Park is a beautiful urban oasis—the 18 acre park, situated in the West Don Lands district of Toronto, boasts a wildlife-filled marsh, athletic fields, playgrounds and plenty of place to sprawl out on grass or host a bbq. But the coolest of the park’s features is the one you can’t see. Built into the sprawling greenland is a plan to protect the surrounding neighborhoods from flood waters. The landscape architects from Michael van Valkenburgh Associates partnered with engineering firm Arup to build a park that looks like nature, but works like a dyke…

Because Corktown Common was developed on a flood plain, the team began by building up the area’s natural elevation. Nearly nine meters of land was added, creating a natural barrier to rising waters. “We had to make sure that the park and the infrastructure were well integrated so that in the end it didn’t feel like a piece of pure infrastructure but felt like a welcoming park that is connected to the urban fabric,” explains Mueller De Celis. This required MVVA to add an additional six meters of topography on top of the original infrastructure. It comes in the form of rolling hills, playgrounds and open green space.

The park is split into a wet and dry side. As water falls on the dry side—whether that be from rainfall, flood waters or from the water playground—it gets collected and directed through a series of underground pipes into a cistern. This water is then reused for irrigation. MVVA says it expects the water to be used anywhere from two to four times before it evaporates. Beyond sustainability, this system also has the added benefit of relieving pressure from the mouth of the Don River by slowing the water flow that dumps into Lake Ontario.

This infrastructure is masked by more than 700 trees, and more than 120 species of plants (95 percent of which are native to the area). Mueller De Celis says that as soon as the marsh was implemented, wildlife bloomed in what used to be a browned-out, post-industrialized area. She recalls one day when she was giving a tour of the park. There was construction happening in the neighborhood, as usual. “The people who were touring couldn’t hear me, not because of the construction but because of the frogs,” she recalls. In the process of building development-enabling infrastructure, Toronto has found itself with a real ecosystem in the middle of the city (no wildlife was reintroduced). As Mueller De Celis puts it: “It might be a constructed landscape, but the wildlife don’t know that.”

Building parks in floodplains is not a new idea – it can be a good use for that space and flooding then does not damage as much. But, this sounds more unique in protecting a surrounding urban area and providing space for development. And, it sounds like all of this is hidden out of sight from people in the park, making it yet another piece of important infrastructure that works best when no one notices it in the background.