Some notes on signs around the cache. First, we know the sign for the bioretention basin/rain garden is getting hard to read, please just do the best you can. (Please let us know if it becomes illegible.) Second, per the City of Montgomery, while the area around here is under development, the parking area and demonstration garden remain open -- just don't go further off Maxwell Boulevard than the parking area.
There is no physical cache container to find; to log this earthcache, you will need to email us the answers to the questions below. To log this earthcache, email us or send us a message and copy and paste these questions, along with your answers. Please do not post the answers in your log, even if encrypted. There's no need to wait for confirmation from us before you log, but we will email you back if you include your email address in the message. Group answers are fine; just let us know who was with you.
1. The name of this earthcache: Maxwell Boulevard Bioretention Basin.
2. Name two of the native plants recommended for use when planting a rain garden. (Bonus points if you can identify the plants used in this demonstration garden.)
3. Name two of the other ways you can help keep Alabama's rivers clean other than plant a rain garden.
4. Why do you think this location is a good place for a rain garden?
5. Is there any water in the basin now? If so, how much? (If you know, how long has it been since it rained in the area?)
Bioretention basins or rain gardens are shallow planted depressions designed to retain or detain stormwater before it is discharged downstream. While the terms "bioretention basin" and "rain garden" are often used interchangeably, there is usually a difference in scale: rain gardens are typically smaller, such as in yards, while bioretention basins might serve to catch runoff from an entire neighborhood or other larger area.
Runoff can damage rivers and creeks if it drains too quickly and causes erosion or flooding. If the runoff contains pollutants or excess fertilizer, it can harm the riparian ecosystem. Bioretention basins are designed to catch excess runoff, filter out any contaminants, and let the water slowly seep away into the water table.
Surface runoff is directed into shallow, landscaped depressions. These depressions are designed to incorporate many of the pollutant removal mechanisms that operate in forested ecosystems. During storms, runoff ponds above the mulch and soil in the system. Runoff from larger storms is generally diverted past the facility to the storm drain system. The remaining runoff filters through the mulch and prepared soil mix. The filtered runoff can be collected in a perforated underdrain and returned to the storm drain system.
The surface should be soil combined with mulch to act as a filter for contaminants and particulate. Below the surface, about 15-20 inches below the surface, another layer, typically sand, helps drain the water out into the surrounding soil. Local plants should be used in these basins, preferably plants that can survive being immersed in water for a time. Why local plants? Because they are already adapted to the local soil and climate conditions and don't require additional fertilizer and care.
This bioretention basin demonstration and display was created by the Alabama River Clean Water Partnership.
Sources:
Sign at location
Florida Field Guide to Low Impact Development
U.S. Environmental Protection Agency stormwater pollution resources
Wikipedia, Bioretention and Rain garden