Evaluation of Field Hydraulic Conductivity Data: Comparing Spot Infiltrometer Test Data to Continuous Recession Data

Sustainable infrastructure research has led to an increase in the use of stormwater control measures (SCM). Rain gardens are vegetated SCMs which promote infiltration, evapotranspiration, or both. As the use of rain gardens and other sustainable practices becomes more common, cost effective techniques are needed to determine site properties for design and to assess their performance after construction. A major component of rain garden performance is hydraulic conductivity, which can be determined by infiltration testing. The double-ring infiltrometer test, while commonly used in practice, can take long periods of time to complete. Single-ring infiltrometer tests often use less water and are require less time to implement, enabling more tests to be completed in the same period of time. Seven small single ring infiltrometer tests were performed at a rain garden on Villanova’s campus in Fall 2014 to determine the field hydraulic conductivity of surficial soil in the SCM. The instrumentation at the site used in the field study has been recording the recession rate in the pond over the past twelve years. Comparing the pond recession rate to the field hydraulic conductivity, it was found that the less commonly used single-ring infiltrometer method can be an accurate predictor of SCM performance.