A Perfect Storm Threatening Water Quality WorldWide
Vulnerability of Water Resources
Mounting pressure on water bodies and their surrounding watersheds from stormwater runoff and pollution represents a major threat to water quality in the United States and worldwide. In the U.S., stormwater runoff is the main reason approximately 40 percent of surveyed rivers, lakes, and estuaries are not clean enough for intended uses such as fishing and swimming as required by the federal Clean Water Act, and only 16 percent exhibit good water quality. Non-point source stormwater pollution occurs as water travels over land carrying contaminants and depositing them into waterways or ground water.
Non-Point Source Pollutants and Their Effects
Non-point source pollutants carried in stormwater runoff include toxic chemicals such as herbicides and pesticides, salt from winter de-icing, and oil and fuel from automobiles. Also included are nutrients such as nitrogen and phosphorus from natural and manmade sources such as fertilizers and septic systems. Excessive nutrients (defined as nutrient amounts greater than a receiving water body can process) result in a range of effects including increased algae and plant growth, reduced oxygen, and altered composition of aquatic species. Decreased water quality and clarity is the all too common consequence.
The scale of the stormwater pollution problem is staggering. According to a recent report of the National Resources Defense Council (NRDC), “An estimated 10 trillion gallons a year of untreated stormwater runs off roofs, roads, parking lots, and other paved surfaces, often through the sewage systems, into rivers and waterways that serve as drinking water supplies and flow to our beaches, increasing health risks, degrading ecosystems, and damaging tourist economies.”
While a healthy natural landscape will absorb nearly all rainfall except from the largest and most intense storms, impervious surfaces (pavements, roofs, etc.) prevents natural infiltration of water into and through the soil. Impervious surfaces dramatically increase the volume and intensity of stormwater runoff and its impacts on waterways. As water quickly travels over surfaces, erosion ensues, damaging stream channels. When runoff volumes exceed streams’ natural capacity, the result is the unnatural scouring and deepening of stream channels. Eroded streambed materials, including sediments, debris, and nutrients, are carried and deposited downstream into lakes and estuaries. This process harms benthic habitats and also disrupts human activities such as boat navigation. Channel hydromodification (the alteration of natural water flows from excessive stormwater) is among the most significant contributors to non-point source pollution of waterways.
Standing in the way of solutions to stormwater pollution is a general lack of awareness on the causes and effects of the problem. Closely related are ineffective and/or poorly administered controls—public policies, regulations, enforcement, etc. Perhaps most importantly, few initiatives exist that provide information on the problem and the means for reducing, or even reversing, the impacts of stormwater pollution.
Success in finding a solution requires a decisive shift that, much like the diffuse nature of stormwater pollution itself, is distributed widely and with the consistency, coherence, and established standards capable of addressing the problem at its many and varied sources. Low Impact Development or LID is designed for this purpose. LID manages stormwater as near to its source as possible, allowing for, rather than altering, the natural processes that perform this essential task.
As described in NRDC’s seminal Rooftops to Rivers report:
“Instead of large investments in complex and costly engineering strategies for stormwater management, LID strategies integrate green space, native landscaping, natural hydrologic functions, and various other techniques to generate less runoff from developed land. One of the primary goals of LID design is to reduce runoff volume by infiltrating rainfall water to groundwater, evaporating rainwater back to the atmosphere after a storm, and finding beneficial uses for water rather than exporting it as a waste product down storm sewers. The result is a landscape functionally equivalent to predevelopment hydrologic conditions, which means less surface runoff and less pollution damage to lakes, streams, and coastal waters.”
The need for and benefits of widespread application of LID practices is clear, yet the present pace of implementation is falling behind, with little reason to expect significant improvement in the near future. Current local regulations fail to recognize LID, local reviewers fail to understand its benefits or their responsibility to learn them, while state and federal regulations fail to address the sweep and gravity of the problem. Without accelerating education on and adoption of LID, the severe problems posed by stormwater pollution can be expected to worsen. The principal casualty will be water quality, with profound implications for the environment and economy.
As one recent article reported, “a survey of research on the expected costs and benefits of a national policy that would induce widespread adoption of LID stormwater solutions found that the benefits would exceed the costs by at least $34 million per year and a review of case studies found that LID stormwater management yielded better environmental outcomes at an average of 25% lower costs than conventional infrastructure.” Yet, as also reported: “Many impediments slow adoption of sustainable stormwater management practices including transaction costs in the process of changing local building codes and training personnel in the construction to make LID development possible.” (2013 Choices Magazine)
Studies on LID practices and their benefits show a clear opportunity for initiatives that foster understanding and catalyze the implementation of LID practices at the pace and scale demanded by the problem. Rising to the challenge and responding to the opportunity is a process that harnesses the power of private initiative to solve problems. The LID Certification™ System at Lake George equips and empowers public and private citizens with the tools needed for wide-scale and effective implementation of LID practices. The guiding goals of LID Certification is clear: to filter every drop of water from our built environment before it reaches streams and the lake, to enable natural controls that reduce stormwater runoff, and to protect the health of the Lake George ecosystem.