rain garden Tag

What I’ve Learned About Bioretention: Part 2

Read Part 1 of this post here. 2. Bigger is not better Like most everything we design, when big things fail, they fail in a big way. Bioretention works best in applications where the drainage area to an individual cell is less than about a quarter acre. Larger bioretention areas are more likely to fail due to erosion because of larger flows, creation of low spots due to variations in the surface, and clogging of the surface layer. This can be avoided by dividing the area into multiple cells with smaller drainage areas. [caption id="attachment_6401" align="aligncenter" width="770"] Larger basin divided into three cells[/caption]   The largest bioretention area I know of is an example of this. Designed by others, it collects runoff from several acres at a highway rest stop. The measures designed to evenly distribute incoming flow have been overwhelmed by large flow rates, the engineered soils mix layer does not drain quickly enough, and...

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What I’ve Learned About Bioretention: Part 1

Bioretention areas (also sometimes called rain gardens) are a very useful tool in the toolbox of stormwater treatment BMPs. They provide a high level of pollutant removal and runoff volume reduction, and, if properly designed, require little maintenance. Bioretention was developed to mimic the hydrology of a natural forest. It consists of a shallow (typically 4-8 inches) basin with 3 inches of mulch and a variety of selected plants on the surface that can accommodate periodic flooding and drought. Under the mulch is a layer of engineered soil mix (typically 12-36 inches). The basin collects surface runoff and filters out nitrogen and phosphorus (nutrients for plants, but pollutants in stormwater) as water passes through the engineered soil mix. Water is absorbed by surrounding soils or is collected by an underdrain. The plants convert the nitrogen and phosphorus collected in the engineered soil mix into woody plant matter and leaves. If designed and...

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Chesapeake Bay Stewardship Program Supports Edible Rain Garden Project in Richmond

Here is a great story about how private corporations and non-profits work together. The National Fish and Wildlife Foundation’s Chesapeake Bay Stewardship Program's funding comes from private companies including Altria, Shell, CSX, Walmart and FedEx as well as federal agencies including the Environmental Protection Agency, the Natural Resources Conservation Service and the U.S. Forest Service. In Richmond the Chesapeake Bay Stewardship Fund monies will fund an improvement project that not only provides educational outreach to the Church Hill area of Richmond ,but will also provide healthy food options for neighborhood families and a cleaner Chesapeake Bay. It is a win-win-win. Watch covereage of the grant award and learn more about the project from WTVR News Channel 6 Read more about the Church Hill Activities and Tutoring program on their web site at:

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Making a Difference in Your Own Front Yard

This article is an important reminder that when all of us do something small, it adds up to something big. I live in Richmond's Combined Sewer Overflow (CSO) area. One small thing I have done is to disconnect our downspouts from the sewer system. Before, the rain ran directly into the sanitary sewer every time it rained. Now (see photo), the the water from our downspout soaks into the ground and helps the flowers in our front yard make it through our long hot summer. [caption id="attachment_1079" align="alignleft" width="620"] Rainfall from the Telfer rooftop has been redirected to provide irrigation for a flower garden in the front yard (Look for blooming photos later in the spring.)[/caption]...

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Urban Stormwater Runoff – It Is a Concern Even During Election Season

First order of business for today: Vote. Voting is our collective civic duty and responsibility. [caption id="attachment_924" align="alignleft" width="300"] Chimborazo Elementary School Rain Garden[/caption] Bacon's Rebellion is a one of Virginia's leading politically non-aligned portal for news, opinions and analysis about state, regional and local public policy, so some might find it surprising that over the weekend - just days before a national election in which Virginia could play a critical role in who occupies the White House - readers would learn more about a small rain garden installed by the City of Richmond earlier this summer at Chimborazo Elementary School. Truth is, the City of Richmond has probably been receiving  more negative publicity for it stormwater program as of late than it has for the improvements that the program was created to fund. Recent articles in the Richmond Times-Dispatch and other media have stated that collections for the City's stormwater utility fee have been poor...

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Putting the LID on Stormwater Runoff

The following post is provided by guest blogger Thomas Powers, P.E., LEED AP, CFM, CPESC, A Project Manager with Wight & Company in Chicago Illinois and former colleague of The Inlet's Carolyn Howard. [caption id="attachment_688" align="alignleft" width="234" caption="Thomas Powers, PE, LEED AP, CFM, CPESC"][/caption] How many gallons of rain do you think falls each year on just one acre of land in Norfolk, Va.? Ten thousand? One hundred thousand? Would you believe more than one million? Unfortunately, most of that water isn’t absorbed by the land and instead becomes stormwater runoff, carrying debris, chemicals, sediment or other pollutants. The U.S. Environmental Protection Agency (EPA) ranks urban runoff and storm-sewer discharges as the fourth most prevalent source of impairment of our lakes, streams and rivers. The current best practices in stormwater management is called low impact development (LID), which refers to a comprehensive land planning and engineering design approach that emphasizes conservation and the use of...

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