Conway's Bioretention Cell on Stone Dam Creek 🌎 EarthCache

The city of Conway created Martin Luther King Jr. Square to honor Dr. King and and the legacies of many local African Americans who made history in Conway. The square also incorporated a strategy for improving the water quality in Conway by constructing a bioretention cell. This is also referred to a Low Impact Development for ecologically based stormwater treatment technology in an urban environment. This park aims to slow, spread, and infiltrate water, thereby mitigating flooding while also allowing plants to treat and clean stormwater runoff. This will help improve the water quality in our area.

Per the Environment Protection Agency’s website (EPA), Bioretention is a best management practice developed in the early 1990’s by Prince George’s County, MD, Department of Environmental Resources. Bioretention utilizes soils and both woody and herbaceous plants to remove pollutants for the storm water runoff. Runoff passes first over or through a sand bed, which slows the runoff's velocity, distributes it evenly along the length of the ponding area, which consists of a surface organic layer and/or ground cover and the underlying planting soil. The ponding area is graded, its center depressed. Water is ponded to a depth of 15 centimeters (6 inches) and gradually infiltrates the bioretention area or is evapotranspired. The bioretention area is graded to divert excess runoff away from itself. Stored water in the bioretention area planting soil exfiltrates over a period of days into the underlying soils.

As you walk around the square using the sidewalks, you will notice the Green Infrastructure features that include: 

1. Permeable Paving - allows water to flow through hardescape and infiltrate into the ground, removing sediment and trapping pollutants
2. Infiltration Basis - large, shallow areas with permeable soils design to temporarily detain and infiltrate stormwater runoff
3. Rain Garden - vegetated depression design to treat water as it passes through roots and infiltrates into the ground.
4. Bioswales - planted depression designed to treat water through phytoremediation as it is conveyed further downstream
5. Vegetated Walls - utilize vertical water harvesting to treat water and reduce stormwater runoff loads.

At the coordinates, you are standing in the Lake Conway – Point Remove Watershed. The water you see flows eventually to Lake Conway, the largest Arkansas Game & Fish Lake in the state, via this location as part of Stone Dam creek. From Lake Conway, water eventually flows into the Arkansas River.

Nitorgen and phosphorus are the two primary industrial polluntants this bioretention cell is mitigating. The plants in this rain garden process pollutants via phytostabilitzation, phytogegredation, and phytohydraulics. The plants help trap pollutants in their roots via phytostabilization, which is the ability of plants to sequester certain contaminants in the plants' roots. This is accomplished through several of the plant's physiological mechanisms. The transport proteins associated with the root also can irreversibly bind and stabilize target contaminants.  Secondly, break down pollutants into less toxic compounds via phytodegredation, which is the ability of plants to take up and degrade the contaminants. Contaminants are degraded through internal enzymatic activity and photosynthetic oxidation/reduction.,Finally filter water through plant tissues phytohydraulics, which is the ability of plants to capture, transport, and transpire water from the environment. This action in turn contains pollutants and controls the hydrology of the environment. This third mechanism does not degrade the contaminant. 

Parking is available along Markham Street. The Square also provides picnic tables and a playground. 

To log the Find:

Read through the information on the cache page and the information plaques at the posted coordinates in the square. Create your answers on what you learned and the observations you made in the square. Message your answers to me via the message center. You do not need to wait for a reply from me to log the cache as found, however I will contact you if there is a problem with your answers. Please do not post photos of the information plaques in your log, but any and all other photos are welcome.

1. Why are plants integral to the design of the rain garden cell for cleaner water?
2. What features of the rain garden do you see that reduce the water’s velocity while raining? Starting with falling rain, describe the water’s path before it reaches the creek.
3. Please include a photograph of one of the Green Infrastructure feature that you enjoyed learning about, you have the option of appearing in that photo, but it is not required. 

🥇🌎 Congratulations to Reese486, JAM6100, and Ubu for the Co-FTF! 🌎🥇