rain garden

Low Impact Development for Los Angeles: The Dollars Make Sense

One of the most exciting things about low impact development projects is that they usually save developers and communities money.

In fact, according to a 2007 study by the Environmental Protection Agency, which examined the costs of construction projects that incorporated LID design principles across the country, LID projects are typically less expensive than construction projects that utilized traditional water management strategies.

Details of the Study

The EPA study – which only considered capital costs, and did not examine the social, environmental or communal benefits provided by LID – found that most LID projects cost only 15 to 80 percent as much as those projects that relied on traditional water management strategies.

You can download the entire study here (PDF), but a few examples include:

  • Auburn Hills – a residential community in southwestern Wisconsin – was constructed in a clustered fashion, to protect and retain green spaces. The project utilized several LID principles, and cost the developers approximately $1.6 million. If the developers had utilized conventional water management techniques, the neighborhood would lack the aesthetic appeal and small ecological footprint that it enjoys. Additionally, if the developers had utilized traditional storm water management strategies, the project would have cost an estimate $2.36 million. Therefore, the developers saved approximately three-quarters of a million dollars (32% savings) and built a superior subdivision in the process.

  • Developers utilized LID principles when designing a conservation-minded, mixed-use development in Mill Creek, Illinois. By incorporating vegetated swales, leaving many natural areas intact and using more permeable surfaces than traditional strategies call for, the developers constructed each lot for approximately $9,000. If traditional water management strategies had been used in the construction process, each lot would have cost $12,000 to prepare.

  • By using low impact development principles, Bellingham City, Washington enjoyed incredible savings during a parking lot renovation project. Rather than spending an estimated $27,000 on the project by installing large underground storage vaults to contain rainwater, they utilized rain gardens to absorb runoff water and completed the project for a measly $5,600 and change. In this extraordinary case, LID principles allowed the city to reduce capital costs by 80 percent.

While usually effective and affordable, LID is not a magic bullet, suitable for every property and community. LID principles can raise the costs of construction in some rare instances, so it is important to examine such decisions carefully. For example, a project in Kensington Estates, Washington incorporated LID principles, but the costs were twice as high as they would have been, had they elected to employ traditional techniques.

Ancillary Benefits

Because LID principles allow plants and trees to do the heavy lifting, such areas are invariably greener than they would otherwise be. In addition to the serving a greater good and helping to protect southern California’s habitats and climate, communities and properties featuring low impact development principles enjoy a variety of direct benefits. For example, well-planted properties demand higher sale prices than similar properties that lack these natural amenities.

According to a 2010 study in Portland, Oregon, homes with street trees sold for an average of $7,000 more than those homes without street trees. However, even those that had no street trees – but were adjacent to homes with trees – sold for about $1,600 more than comparable homes.

Additionally, trees and natural landscapes provide cultural benefits (such as reduced crime rate), health benefits (including decreased recovery times and lower stress levels) and create “green collar” jobs.

Funding Strategies

With luck, the City of Los Angeles will enact a LID ordinance, which will require newly constructed roads and other infrastructural components to incorporate Best Management Practices (BMPs) – which are those items and strategies that reduce runoff water pollutants — in their designs.

However, to enact such ordinances, city officials must first allocate – or prescribe a mechanism to generate – funds for enactment and enforcement. Additionally, while BMPs will usually lower the costs of new construction projects, funding is necessary for BMP installation in existing properties.

A 2009 report, entitled “Green Infrastructure for Los Angeles: Addressing Urban Runoff and Water Supply Through Low Impact Development,” by Haan?Fawn Chau, of the University of California, Los Angeles, addressed some of these issues. According to the report (PDF), numerous funding strategies are feasible, including:

  • Establishing a one percent tax on new construction

  • Installing parking meters in suitable locations

  • Private Foundation Grants

  • Federal and State Grants

  • Constructing new parks and utilizing the Quimby fees for LID projects

  • Corporate sponsorship

  • Public-Private cooperative efforts

  • Parcel drainage fees (IPAs).

All of these approaches have benefits and drawbacks, which should be the subject of vigorous, informed debate by all stakeholders – including the general public. However, the important thing is that a funding method is selected and low impact development approaches replace traditional storm water runoff management techniques.