Matthew P. Jones

Bioretention Impact on Runoff Temperature in Trout Sensitive Waters

A study was conducted in western North Carolina, along the southeastern extent of the U.S. trout populations, to examine the effect of bioretention areas on runoff temperature. Four bioretention areas were monitored during the summers of 2006 and 2007. It was found that smaller bioretention areas, with respect to the size of their contributing watershed, were able to significantly reduce both maximum and median water temperatures between the inlet and outlet. The proportionately larger bioretention areas were only able to significantly reduce maximum water temperatures between the inlet and outlet; however, these systems showed evidence of substantial reductions in outflow quantity, effectively reducing the thermal impact. Despite temperature reductions, effluent temperatures still posed a potential threat to coldwater streams during the peak summer months. During the summer months, effluent temperatures were generally coolest at the greatest soil depths, supporting evidence of an optimum drain depth between 90 and 120 cm. The ability of bioretention areas to reduce storm-water temperature and flows supports their application to reduce the thermal impacts of urban storm-water runoff.

Effect of Storm-Water Wetlands and Wet Ponds on Runoff Temperature in Trout Sensitive Waters

With increasing development in areas of trout sensitive waters, the effect of urban storm-water runoff temperature on the aquatic ecosystem has become a concern. A study was conducted in western North Carolina, along the southeastern extent of U.S. trout populations, to determine the effect of storm-water wetlands and wet ponds on the temperature of urban storm-water runoff. Measurements included temperature at the inlets, outlets, and at several depths within the best management practices (BMPs). Parking lot runoff temperatures were significantly higher than the 21°C temperature threshold for trout during peak summer months and water temperatures consistently increased from the inlet to the outlet in the storm-water wetland and wet pond, implicating these BMPs as sources of thermal pollution. Despite similar inflow temperatures, effluent temperatures from the wet pond were significantly warmer than those from the storm-water wetland for the period from June to September. Substantial cooling was observed ...

Effect of Urban Catchment Composition on Runoff Temperature

AbstractUrban runoff adversely impacts cold-water stream environments due to sporadic fluxes of thermally enriched runoff. This adversely impacts tourism in regions that support trout and salmon streams. Research on storm water control measures (SCMs) has shown that meeting the 21°C trout threshold is not consistently feasible with current SCM technologies. Thus, it is important to consider other factors in storm water temperature management, such as catchment characteristics. Median and maximum runoff temperatures from a shaded parking lot were consistently lower than those from a nearby unshaded lot. This suggests the need to implement a tree canopy cover in trout-sensitive catchments. A light-colored chip seal pavement was compared to a traditional hot-mix asphalt pavement; the light-colored chip seal produced median storm water temperatures that were 1.4°C lower than the standard hot-mix asphalt. It was shown that runoff temperature measurement location is critical when evaluating SCM performance, and...

The Effect of Stormwater Wetlands and Wet Ponds on Runoff Temperature in Trout Sensitive Waters

While the effect of stormwater wetlands and wet ponds on conventional pollutant loads has been well researched, the effect of these systems on water temperature, an important habitat constraint for many aquatic organisms, is not well understood. A monitoring study was conducted at a stormwater wetland and wet pond in western North Carolina, along the southeastern extent of trout populations in the U.S., to determine the effect of these BMPs on runoff temperature and identify any design parameters that potentially influence effluent temperatures.

Rainwater Harvesting for Household Irrigation in the Southeastern United States

In the southeastern United States, little emphasis has historically been placed on household water conservation and alternate water supplies due to the humid climate of the region. Resulting in part from the impact of recent droughts and increased public awareness of water supply issues, interest has developed in installing rainwater harvesting systems to meet household demands for non-potable water.

Performance of Rainwater Harvesting Systems in the Southeastern United States

Due to recent concerns over the environmental impact of stormwater runoff and increased water demands, interest in rainwater harvesting systems has developed in humid, well developed regions, such as the southeastern United States. In order to better understand the anticipated usage and reliability of rainwater harvesting systems in the southeastern United States, a monitoring study was conducted at 3 rainwater harvesting systems in North Carolina, measuring cistern water levels and rainfall. Results of the monitoring study showed that the rainwater harvesting systems were typically underutilized. Water usage was most consistent at the location where harvested rainwater was used to flush a toilet; however, the water level within the cistern only dropped below 80% of capacity on one occasion during the 30 month monitoring period. A computer model was developed to simulate the performance of rainwater harvesting systems based upon historical rainfall data and anticipated usage by evaluating a daily or hourly water balance. The rainwater harvesting computer model was used to simulate the performance of a 55-gallon (208 liter) rain barrel commonly used by homeowners in this region to meet household gardening demands. A variety of turfgrass irrigation scenarios were examined, varying the size of the irrigated area and contributing rooftop. Simulation results showed that the rain barrel was not able to adequately meet irrigation demands. The low volume of water the rain barrel was able to supply for irrigation and the large amount of overflow indicated that the rain barrel was not able to effectively utilize the potential water supply coming from the rooftop and provided minimal runoff volume reduction.

The Effect of Bioretention on Runoff Temperature in Trout Sensitive Waters

As urbanization continues to encroach upon coldwater fisheries, the effect of heated stormwater runoff on the coldwater aquatic ecosystem has been realized; however, the effect of stormwater BMPs on runoff temperature is largely unknown. There are indications that bioretention could discharge cooler effluent than stormwater wetlands and wet ponds, since the outlet is located at the bottom of the system where soil is insulated from elevated temperatures near the surface. Infiltration through soil media is generally considered to reduce runoff temperatures, with many coldwater streams able to maintain their cooler temperatures through influxes of groundwater. A monitoring study was conducted at 4 bioretention areas in western North Carolina, along the southeastern extent of United States trout populations, to determine the effect of bioretention on runoff temperature and identify any design criteria that affect effluent temperatures.