Best Management Practices (BMPs) - Solutions for Tahoe
Regional Green Building and Living Green Resource Guide
BMPs are those “Best Management Practices” which make a significant difference in improving the quality of storm water runoff. To protect streams and lakes from pollution (tiny particulates and nutrients) contained in runoff, we must infiltrate that runoff, or treat it, as near to its source as is practicable. Runoff is the rain or snow melt which “runs off ” impervious surfaces such as roof tops and pavement (roads, parking areas, and so on). The idea is to employ the best procedure, strategy, method or technology to achieve the optimum desired results with the least harm.In the site-specific world of storm water quality, we strive to infiltrate all of a site’s storm water and snow melt on the site with the goal of improving water quality to protect wildlife, drinking water, and recreational water resources. One strategy, often referred to as “source control,” eliminates runoff in the first place. This means we attempt to infiltrate (soak into the ground) the potential runoff before it “runs off.” Source control also includes minimizing impervious surfaces.
When we infiltrate storm water, we allow the soil ecosystem to do what it has done for millennia; to filter and digest pollutants and recharge ground water. Recharging ground water aquifers is an important benefit of functional BMPs. Sometimes referred to as “Low Impact Development” (LID), the idea is to restore a developed site to its pre-development hydrologic condition and/or design new development to mimic the pre-development condition. We create systems that utilize sheet flow and infiltration, instead of concentrated piped flows.
What are some actual examples of good BMPs? The state of Colorado has a wonderful manual (also available in Spanish) titled “Green Industry Best Management Practices for the Conservation and Protection of Water Resources in Colorado” (http://www.greenco.org). Locally, the Tahoe Regional Planning Agency (TRPA) has also produced “How to Install Best Management Practices in the Lake Tahoe Basin” (www.trpa.org). These are a couple of excellent resources for homeowners and professionals alike.
For the generally sandy soil types of the central Sierra and the Western Great Basin, some of our favorite LID strategies include: vegetated or mulched soil, berm and swale, shallow detention basin, simple curb break to sheet flow, bio-swale, bio-retention basin, integrated landscape and storm water systems, pervious paving and green roofs.
BMPs offer numerous benefits to the environment, community, and regional economy. These include but are not limited to:
- Improved water quality in streams and lakes
- Improved public health
- Improved biodiversity in waterways
- Improved recreational resources
- Improved quality of tourism
- Improved ground water recharge
- Reduced public infrastructure costs
- Reduced public health care costs
- Reduced cost of maintenance and repair to infrastructure
- Reduced dust and air pollution
- Reduced “heat island” effect
- Increased economic gain-new industry, tourism, jobs, and so on
- Caché as an environmentally friendly region
- Reduced demand for air conditioning, lighting
- Reduced need for sanding roads in winter
- Reduced need for snow removal
Perhaps the most important opportunity of BMP design is the “Integrated System Approach,” or ISA. The simple fact that each site (property) is unique creates the need for site specific design. There are no “one size fits all” BMPs. In fact, most sites require a variety of strategies to best resolve runoff issues.
ISA allows an experienced designer to draw on years of field work and observation to create a site specific plan which incorporates a variety of solutions as dictated by the site. This is how we achieve the best performing and most aesthetic solutions.
In our region, the TRPA, and recently the Truckee River Watershed Council (http://www.truckeeriverwc.org/), offer short training sessions to expose the public and professionals to BMPs. However, a three hour or one day clinic does not make a person an expert in any field. BMPs do not need to be highly complex, but they do need to be designed and installed properly to achieve the most benefit with the least harm.
As Andrew T. Ryan, PE has noted, “EcoDesign ‘closes the loop.’ It’s not okay to make clean water here by making dirty water somewhere else.” He is referring to the sometimes “hidden” environmental impacts of BMPs. What is the environmental impact of mining and production associated with precast concrete facilities such as drop inlets? What about mining rock for rock-lined swales or rock filled trenches? What about the digging of basins and disposal of spoils? What about the plastic structures used to create underground vaults and void space? What about the fossil fuels required to mine, process, transport, install, remove and dispose of these manufactured facilities. This is just the tip of the iceberg when it comes to assessing whole life cycle costs.
As we begin to have a deeper understanding of our design solutions and the impacts associated thereof, we begin to realize the significance of designing for optimized performance with minimized impact (local, regional,and global). In large part this means letting nature do the work. Simple solutions which rely on minimal earthwork and maximum vegetation should be the foundation of our design method. ISA and experience lead us from simple to more complex when simplicity proves insufficient.
Improving water quality through the use of BMPs is an exciting and important challenge offering numerous benefits to the environment, community and the economy. We envision a “School for Sustainable Trades” where young and old alike can learn the skills of design and installation of BMPs. Science, the regulatory community and field experience would combine in an iterative process to create the best solutions with most benefit and least impact. Around the world, municipalities in Australia, England, Oregon, Canada, and elsewhere are embracing this opportunity for environmental, community, and economic benefit.
Water quality and environmental quality are now mainstream goals with economic and community sustainability as naturally resulting benefits. Embracing the work of good BMPs is part in parcel of the new ‘eco’-nomics. It’s an exciting time for creative solutions.
Tony D. Pastore is a principal with Pastore-Ryan, an EcoDesign, Engineering and Green Building firm in Kings Beach, California. He is a certified TRPA BMP Designer/Installer, NRMCA Certified Pervious Concrete Technician/Trainer, Certified Permaculture Designer/Instructor, has over 15 years experience as an ecological landscape designer/builder, and has guest lectured on these subjects.