Bioretention has been the principal form of Low-Impact Development (LID) used to slow, treat, retain and infiltrate stormwater runoff, mimicking a site's natural, pre-development hydrology. One aspect of bioretention that has some scientists and regulators concerned is the phenomenon known as nutrient leaching. Nutrient leaching occurs when the bioretention media, which often contains compost, breaks down and releases phosphorus to downstream receiving waters.

Since its inception in 1996, The International Stormwater BMP Database  has been archiving performance, design, and cost data for stormwater treatment best management practices (BMPs) in a publicly accessible database.  At this point, over 600 BMP studies have been added, providing a wealth of information to regulators, engineers, academics, and

The International Stormwater Best Management Practices (BMP) Database project website (http://bmpdatabase.org) features a database that includes over 600 BMP performance studies.  This is a tremendous free resource for engineers, scientists, policymakers and others who seek to characterize the pollutant removal and hydrologic performance of various

At about 2.5% of the total water volume on the planet, we’ve always had roughly the same amount of freshwater.  Unfortunately, it seems that, at the local level, the amount of fresh water made available through precipitation is increasingly erratic, with the last year featuring historic floods in the eastern US and historic drought in the west.  In

Perhaps the most recognized Low Impact Development technique, bioretention, incorporates landscaped features to slowly percolate stormwater runoff through plants and engineered soil prior to infiltrating that water into native soils. Where feasible, these systems can be a low cost, high efficiency stormwater management practice that can also

Infiltration plays an increasingly important role in meeting stormwater runoff mitigation regulations. One of the primary considerations for infiltration feasibility is the runoff routing.Infiltration systems must drain in a reasonable amount of time to avoid creating mosquito habitat and to recover storage volume for subsequent storms. Drain down

Mother Nature’s soil is the best of all urban stormwater Best Management Practices (BMPs). Precipitation infilitrates the soil, reduces runoff, filters and captures most pollutants, recharges groundwater, and maintains a diverse, self-sustaining biological community.Conservation of natural soils and urbanization are diametrically opposed. When

By now, you’ve probably heard of triple bottom line accounting, a full cost accounting approach considering the economic, environmental and social impacts of a decision or more poetically, the three P’s: people, planet and profit. In the stormwater infrastructure planning world, as in many other urban planning arenas, this approach is gaining

Inspection and maintenance are key factors for making sure that your biofiltration box is performing as designed and achieving the required water quality standards.  Here are a few things to keep in mind...1. Protection from Construction DebrisBioretention box soil must be protected from compaction by heavy equipment traffic during construction.