Hydrologic Monitoring: Legacy Parkway Wetlands, Utah

Presenter Information

Craig Forster

Location

ECC 307/309

Event Website

http://water.usu.edu/htm/conference/past-spring-runoff-conferences

Start Date

4-5-2007 1:30 PM

End Date

4-5-2007 1:50 PM

Description

The dynamics of wetland hydrology along the east shore of the Great Salt Lake (GSL), Utah are revealed by monitoring shallow groundwater levels in a network of piezometers located along the southernmost 7 miles of the Legacy Parkway. More than 20, 3- piezometer nests (depths range up to 6 meters below ground surface) have remained operational over the past 6 years. Located in a semi-arid environment (annual precipitation is about 14 inches per year with most arriving during the winter season), the wetlands are fed, in part, by precipitation that falls on the Wasatch Mountains (east of the wetlands) and moves westward towards the saline GSL (west of the wetlands). The piezometer network was installed to aid in highway drainage design and to provide a foundation for assessing the potential impact of highway construction on wetland hydrology. Specific monitoring goals included: 1) assessing depths to groundwater along the Parkway, 2) establishing the timing and magnitude of future groundwater fluctuations along the Parkway, and 3) identifying the source of water supplying wetlands immediately adjacent to, and west of, the Parkway. Shallow groundwater levels in all piezometers rise to a maximum in the Spring and decline to a minimum in the Fall with an annual variation of about 1 meter. The groundwater level fluctuations correspond in time with the smaller lake level fluctuations of the nearby GSL (about 0.5 meters during the period of groundwater monitoring). During the period 2000 through 2004, the GSL lake level declined about 2 meters in response to the recent drought. Because shallow groundwater levels along the Parkway did not decline during the same period, it seems reasonable to conclude that wetland hydrology is not directly impacted by fluctuations in the GSL unless the wetlands are inundated by a rise in the GSL. An artesian aquifer located below the wetlands likely supports the shallow groundwater system of the wetlands via leakage through intervening low-permeability aquitards. The seasonal declines in shallow groundwater levels suggest that summer-time evapotranspiration rates exceed the rate of wetland recharge by the underlying artesian aquifer. The lack of evapotranspirative discharge during the winter and spring enables the underlying aquifers to recharge the shallow system before declining the next summer.

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Apr 5th, 1:30 PM Apr 5th, 1:50 PM

Hydrologic Monitoring: Legacy Parkway Wetlands, Utah

ECC 307/309

The dynamics of wetland hydrology along the east shore of the Great Salt Lake (GSL), Utah are revealed by monitoring shallow groundwater levels in a network of piezometers located along the southernmost 7 miles of the Legacy Parkway. More than 20, 3- piezometer nests (depths range up to 6 meters below ground surface) have remained operational over the past 6 years. Located in a semi-arid environment (annual precipitation is about 14 inches per year with most arriving during the winter season), the wetlands are fed, in part, by precipitation that falls on the Wasatch Mountains (east of the wetlands) and moves westward towards the saline GSL (west of the wetlands). The piezometer network was installed to aid in highway drainage design and to provide a foundation for assessing the potential impact of highway construction on wetland hydrology. Specific monitoring goals included: 1) assessing depths to groundwater along the Parkway, 2) establishing the timing and magnitude of future groundwater fluctuations along the Parkway, and 3) identifying the source of water supplying wetlands immediately adjacent to, and west of, the Parkway. Shallow groundwater levels in all piezometers rise to a maximum in the Spring and decline to a minimum in the Fall with an annual variation of about 1 meter. The groundwater level fluctuations correspond in time with the smaller lake level fluctuations of the nearby GSL (about 0.5 meters during the period of groundwater monitoring). During the period 2000 through 2004, the GSL lake level declined about 2 meters in response to the recent drought. Because shallow groundwater levels along the Parkway did not decline during the same period, it seems reasonable to conclude that wetland hydrology is not directly impacted by fluctuations in the GSL unless the wetlands are inundated by a rise in the GSL. An artesian aquifer located below the wetlands likely supports the shallow groundwater system of the wetlands via leakage through intervening low-permeability aquitards. The seasonal declines in shallow groundwater levels suggest that summer-time evapotranspiration rates exceed the rate of wetland recharge by the underlying artesian aquifer. The lack of evapotranspirative discharge during the winter and spring enables the underlying aquifers to recharge the shallow system before declining the next summer.

https://digitalcommons.usu.edu/runoff/2007/AllAbstracts/25