Rain Garden Prototype at Boys Choir Lot

The GILL monitoring set up at the BCL includes 12 rain garden prototypes. The main goal is for this site is to perform a comparison analysis between outflow rates and soil moisture data from prototypes with different hydraulic loading ratios and soil mixtures.

Design configurations for prototypes and power supply distribution at the BCL. The bottom layer soil in all prototypes includes 18 inches of gravel AASHTO #57. The top layer soil for prototypes is 12 inches of high sand soil (prototypes 1, 2, 5, 6, 9, and 10) and standard stormwater infrastructure soil (prototypes 3, 4, 7, 8, 11, and 12). HLR values represent the Hydraulic Loading Ratio for the prototypes as defined on the diagram.

Monitoring systems at the BCL:

Monitoring systems at this site include soil Decagon soil moisture probes inside the barrel soil (10-HS and EC-5), scales under the barrels, and outflow measurement box in from of the barrel. These inputs are wired for each scale into an Arduino Uno with a data logging shield.  A set of shallow and deep soil moisture probes are implemented in the soil to monitor the infiltration time. Data from the scale helps for mass balance analysis before and after rain events to approximate soil water retention. Finally the outflow measurement system is designed to measure the outflow rates from the system which indicates the field capacity of the rain garden and helps closing the mass balance. The following figure demonstrates some monitoring results from the BCL experiments.