Incenting Low Impact Development

First-time job seekers and low impact development (LID) pioneers face the same Catch-22: Without prior experience, no one wants to take the risk of giving them a chance, but they can’t get experience unless and until they have an opportunity. By partnering with the development community, local governments can advance the LID cause without pushing already-embattled private developers over the brink. Local governments can utilize three tools at their disposal to help developers overcome regulatory and economic barriers to LID.

LID techniques can address many issues including energy conservation and air quality. To focus the discussion, this article will examine how public-private LID partnerships can speed advances in addressing the environmental problem of stormwater runoff. Stormwater management techniques have evolved rapidly over the past decade, but the typical solution has been to increase the size of stormwater retention and detention facilities.

Treat and release is the name of the game. Over the past few years, a growing body of scientific literature suggests that a better method of treating stormwater is allowing it to seep into the ground and letting natural processes do the work. Developed areas, however, are largely comprised of impermeable surfaces such as roads, parking lots and buildings. Reduction of the proportion of impervious surfaces in urban areas provides a clear opportunity to develop and incorporate LID techniques to the benefit of all.

First, governments and developers need to identify regulatory changes that can be made to facilitate LID. Almost invariably, local jurisdictions incorporate national standards based on those developed by the American Association of State Highway and Transportation Officials (AASHTO).

These standards are both general and focused primarily on functionality, safety, durability and cost. While important, these issues do not necessarily address environmental impacts. For example, AASHTO standards for streets with pedestrian and bicycle facilities are much wider than those without. While the increased width improves safety and may encourage multi-modal transportation, it also significantly increases impervious surfaces.

Accordingly, developers and local jurisdictions could work to modify engineering and design standards to allow for reduced street widths and to require sidewalks on only one side of streets where safety would not be compromised. Sidewalks typically comprise about 10 percent of the total paving costs for a residential development at a cost of about $15 per square yard. For every square foot of sidewalk removed, there is a corresponding one-to-one reduction in the size of the stormwater facilities. Removing half of the sidewalks thus reduces paving costs and runoff, thereby reducing stormwater facility costs, too. Reducing road widths has the same effects. Long-term, less paving means less maintenance. These two simple regulatory changes would have almost no out-of-pocket cost to governments or developers and would yield immediate benefits by reducing stormwater runoff, development costs and long-term maintenance costs.

A related impediment to the implementation of LID techniques are the materials standards adopted by federal, state and local governments for roads, streets and sidewalks. As with any new product, developers using pervious and porous concrete (and similar materials) have gone through a trial-and-error learning curve in developing a durable product as well as identifying appropriate applications. Consequently, local governments have been hesitant at best to allow developers to use such ‘experimental’ materials for sidewalks, much less road surfaces.

Part of the issue is durability, maintenance and, ultimately, who pays for it. With all of this in mind, the second tool for governments and developers is to share in the costs and risks associated with pioneering LID techniques using new materials. While planning for the use of potentially more expensive materials may be difficult in a time of tight budgets, LID provides demonstrable public benefits including reduced stormwater treatment costs.

Second, on a more project-specific level, governments should look for ways to offset increased design and construction costs by providing financial incentives for incorporating LID techniques. For example, standard asphalt costs run about $45 per ton versus $60 per ton for pervious asphalt. Traditional stormwater treatment facilities are often among the costliest pieces of infrastructure of a development however. By using pervious asphalt for all paved surfaces—especially road surfaces—stormwater treatment ponds can be eliminated entirely, reducing overall construction costs by 25 percent to 50 percent.

However, by only allowing the use of pervious asphalt for driveways, parking lots and sidewalks, the corresponding reduction in stormwater facilities may not be sufficient to offset the 33 percent increase in paving costs. This is especially true given that the pervious areas may require the installation of expensive proprietary treatment devices such as composting filters, which cost up to $9,000 per storm drain. Because reduced stormwater runoff reduces burdens on government-owned and operated stormwater facilities such as storm sewers, governments could incentivize the use of LID techniques that reduce runoff by providing credits toward impact fees.

Finally, perhaps the most important tool for public-private LID partnerships is for governments and developers to identify potential pilot projects, in which the government will subsidize some or all of the costs of using LID techniques. Such projects will allow for monitoring and learning about how experimental materials and techniques stand up over time. This tool may require little financial risk in the present political climate as federal “green” funds for infrastructure and development are available. Once a potential LID pilot project is identified, local governments and developers can jointly seek grants to offset costs. These pilot projects, in turn, will provide the necessary experience for future LID developers and governments to rely on when they seek to implement LID techniques on a wider scale. The ultimate goal is to drop the ‘LID’ modifier because the techniques will simply become the standards.

Aaron Laing is an attorney in the Seattle office of Northwest regional law firm Schwabe, Williamson & Wyatt, focusing his practice in the areas of land use and litigation. Mr. Laing can be reached at 206.407.1553 or alaing@schwabe.com.