Top 10 Takeaways: International Low-Impact Development Conference

The American Society of Civil Engineers (ASCE) together with the Environmental and Water Resources Institute (EWRI) host one of the best research-driven conferences we’ve been to about low-impact development, held last month in Houston, TX. Today, L. Peter MacDonagh, FASLA – who spoke at the conference about using trees and soils for stormwater management – will share his Top 7 takeaways from the conference for those who were unable to attend. The conference theme was “LID Works in All Climates and Soils.” As always, this is a totally subjective assessment of the key things to know about based for the design, planning, and arboricultural communities. We hope they entertain and educate.  -LM

7) Taking LID Seriously-Seriously

Low-impact development (LID) is moving into a new phase. For years, many of us professionals have been advocating for its widespread use as a balm to our city’s stormwater problems. Yes to rate control, yes to volume, but most especially yes to water quality improvement. After vast amounts of research and numerous pilot studies, the answer is clear: LID works better and less expensively than the alternatives. I like to say that LID is now exiting its Oddity phase and entering its Commodity phase. Thank goodness!

6) How Fast Can I Talk? How Fast Can I Run?

The LID conference is a classic academic conference in that there were nine (9) 1.5 hour technical time slots over three days, and six concurrent sessions within in each technical time slot. Each talk, including the question and answer period, were less than 20 minutes long – no exceptions.

It’s harder for me to present highlights in 17-18 minutes than in a 30-40 minute talk, and the high number of sessions in this compressed time frame allows lots of papers to be presented. This is particularly useful for professors, who live in the publish-or-perish world of academia, who can list their presented paper on their CV.  However, the LID conference also had consistently excellent content, and struck a very nice balance between research and practice. Full scale field studies testing (paired watersheds) papers are favored over bench tests. This allows a lot more useful applied information to make it into LID practice. Here’s an unexpected advantage to 20 minute talks: very few people fall asleep during presentations, there’s just no time for a guy to get comfortable!

5) Houston: A Beauty Pageant City? Not without trees!

Leaves on trees really dress Houston up. My previous trips to Houston were in the spring, summer and fall. Traveling on Interstate 610 into downtown Houston in leafless, dark and wintry January, however, made me realize how very flat Houston is.

This combination of planar flatness and leafless trees raised my visual awareness of what North America’s largest un-zoned city really looks like. Many Houstonians pride themselves on this un-zoning and attribute Houston’s very large population (4th in the US) and success to this fact alone. It seems to me that if Houston was not also the world’s oil capital, the “no zoning” rule would be extremely hard-pressed to confer such economic success or beauty on this city. Luckily, for 9 months of the year, the tree’s leaves take care of “un-zoning’s” looks.

4) What if Houston Paid Redeveloping Homeowners Directly for LID Detention?

What if aspirational neighborhood of several thousand single family homes (SFH) on modest 6,000 square foot lots was sitting inside the 610 Loop, close to downtown Houston? What if this proximity to downtown offices was dramatically driving up the price of all of these houses? What if this rapidly redeveloping neighborhood was replacing its 1,000 square foot housing footprints with multi-thousand square foot? What if that same neighborhood was upgrading its one-lane driveways to two- and three-lane driveways?

This impervious surface created by this type of development has a huge negative impact to the detention capacity of this neighborhood. At this rate of hard surface increase, the city of Houston would require another 2 acre feet of detention storage per year for this neighborhood alone just to keep its current MS4 permit. Now what happens if this is occurring in several Houston neighborhoods at the same time? In the words of Apollo 13 Astronaut James Lovell…..”We have a problem, Houston!”

Furthermore, there are community challenges to this approach. If Houston were to try and site the necessary detention basin capacity inside a neighborhood’s boundaries, it would require the clearing of 220 houses and the land of these 6,000 square foot lots into a single detention pond. Annually. How do you think the neighborhood would react? Would housing prices go up or down with a brand new several acre detention basin at its center? What would happen to the city’s property tax revenues? Neither would be a popular or winning result.

Instead, what if the city required that each redeveloping lot stored/retained stormwater in each yard? What if LID was retrofitted onto each lot at the time of its redevelopment? What if this LID was only in the form of rain-gardens, trees with large soil volumes, underground cisterns and pervious driveways all hiding in plain sight? What if this redeveloped landscaped lot was invisible to all but the most observant LID & green infrastructure design professionals? What if the city built all of this at no cost to the homeowner?

A solution like this would not result in a loss of the tax base because there is now no need to demolish houses to dig up those lots for a detention basins, and also no up-sizing of the stormwater pipe system. The city would save money on the capital costs, but more importantly, the property taxes collected alone would pay for the system in a few short years. Thanks are due to Kathleen English and Tom Bacus for their excellent presentation on this topic, “Out of Space? Creating Distributed Detention in a Redeveloping Community.”

3) Public Private Partnerships (P3) are key to LID

As municipal budgets have been slashed since the great recession started in 2007, I’ve started to hear more and more about P3s. A few years ago the City of Chicago was in a financial jam and sold the rights to collecting parking fees for all its parking stalls to Wall Street financiers. I’m not sure of the details, but it was a multi-decade lease. Many Chicago colleagues of mine feel that the city was ripped off. Maybe they were, maybe they weren’t; but I’m reading more and more articles in financial journals listing the benefits of P3 as a financing tool to get needed infrastructure built. Larry Coffman gave a great workshop on P3 and how it can get a countywide LID infrastructure system built.

Prince Georges County in Maryland is betting that the best way to finance stormwater infrastructure for water quality is for local government units (LGU) to form public private partnerships (P3) with construction companies (CC) that build, maintain and monitor LID infrastructure to the LGU’s performance standards for rate, volume and quality. Now that the P3 has been created, and the terms, scope, schedule, and cost of their project have been defined and agreed to, the LGU takes its project package to the Municipal Bond Market for sale, where interest rates are much lower than those charged by Wall Street financiers. That’s how urban areas can get LID infrastructure built, at reduced costs while also creating lots of local construction jobs.

In short, almost no U.S. city needs solely private financing to make a P3 model work in getting LID infrastructure built at scale. It’s clear that cities, counties and other special districts with AAA bond ratings certainly don’t, as they can get a much better interest rate and terms on the Municipal Bond Market for the bulk of their project costs.

2) Forget the bake sales

Larry Coffman returned to work with Maryland’s Prince George’s County to set up a countywide LID system with potentially 50,000 devices, 15,000 acres of converted imperviousness, and a $1.2 billion budget for cleaning up stormwater flowing untreated to the Chesapeake Bay. There was no blueprint of distributed LID being implemented as a modified design/build contract (DBFM) using a Public Private Partnership at this scale of stormwater management. So Prince Georges County and Corvias Solutions formed a P3; first they’re starting with a $100 million, 2,000 acre converted imperviousness demonstration for 30 years. This raises LID up as a real player in the field of stormwater infrastructure, all of which has been chronically underfunded nationwide.

We are going to find out how this model works. Will it work perfectly, 100 percent of the time?  Not likely. But if the Department of Defense took the “we won’t build anything unless it’s perfect” approach, no one would have heard of Lockheed Martin or Northrop Grumman, and the US Army and Navy would still be firing cannonballs.

And a drum roll for # 1…

1) Son of LID says thank you!

Larry Coffman, scientist, coined the term LID, and along with Neil Weinstein, engineer and landscape architect, founded the independent 501 (c)(3) non-profit LID Center in 1998. Among other goals, they wanted to put LID into practice and protect Chesapeake Bay from its toxic stormwater runoff. After years of leading the country and the Western Hemisphere on this practice, Larry has just retired. I feel like the appropriate thank you to Larry is the same as the National Park Service said in honoring their first director Stephen Mather: “There will never come an end to the good that he has done.”

Peter MacDonagh, FASLA is the Director of Science + Design at The Kestrel Design Group.

Want to read more of Peter’s Top 10 Takeaways? Click here.


Andre ManoelCC BY-SA 2.0

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