Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jan 1;37(1):78-97.
doi: 10.1089/ees.2019.0146. Epub 2020 Jan 13.

Impacts of Varying Dam Outflow Elevations on Water Temperature, Dissolved Oxygen, and Nutrient Distributions in a Large Prairie Reservoir

Meghan K Carr  1 , Amir Sadeghian  1 , Karl-Erich Lindenschmidt  1 , Karsten Rinke  2 , Luis Morales-Marin  1
Affiliations

Impacts of Varying Dam Outflow Elevations on Water Temperature, Dissolved Oxygen, and Nutrient Distributions in a Large Prairie Reservoir

Meghan K Carr et al. Environ Eng Sci. .

Abstract

Dam operations are known to have significant impacts on reservoir hydrodynamics and solute transport processes. The Gardiner Dam, one of the structures that forms the Lake Diefenbaker reservoir located in the Canadian Prairies, is managed for hydropower generation and agricultural irrigation and is known to have widely altering temperature regimes and nutrient circulations. This study applies the hydrodynamic and nutrient CE-QUAL-W2 model to explore how various withdrawal depths (5, 15, 25, 35, 45, and 55 m) influence the concentrations and distribution of nutrients, temperature, and dissolved oxygen (DO) within the Lake Diefenbaker reservoir. As expected, the highest dissolved nutrient (phosphate, P O 4 3 - - P and nitrate, N O 3 - - N ) concentrations were associated with hypoxic depth horizons in both studied years. During summer high flow period spillway operations impact the distribution of nutrients, water temperatures, and DO as increased epilimnion flow velocities route the incoming water through the surface of the reservoir and reduce mixing and surface warming. This reduces reservoir concentrations but can lead to increased outflow nitrogen (N) and phosphorus (P) concentrations. Lower withdrawal elevations pull warmer surface water deeper within the reservoir and decrease reservoir DO during summer stratification. During fall turnover low outflow elevations increase water column mixing and draws warmer water deeper, leading to slightly higher temperatures and nutrient concentrations than shallow withdrawal elevations. The 15 m depth (540 m above sea level) outflow generally provided the best compromise for overall reservoir and outflow nutrient reduction.

Keywords: dam withdrawal; dissolved oxygen; nutrients; reservoir; temperature; water quality.

PubMed Disclaimer

Figures

FIG. 1.
FIG. 1.
Lake Diefenbaker Reservoir enclosed by the Gardiner and Qu'Appelle Dams. The inflowing South Saskatchewan River and outflowing Lower South Saskatchewan and Qu'Appelle Rivers are included. The CE-QUAL-W2 model boundaries run from the upstream boundary shown in the map down to and including the reach closed by the Qu'Appelle and Gardiner dams.
FIG. 2.
FIG. 2.
July 31, 2011 and 2013 temperature profiles for 5, 35, and 55 m outflows.
FIG. 3.
FIG. 3.
July 31, 2011 and 2013 DO profiles for 5, 35, and 55 m outflows. DO, dissolved oxygen.
FIG. 4.
FIG. 4.
July 31, 2011 and 2013 TP profiles for 5, 35, and 55 m outflows. TP, total phosphorus.
FIG. 5.
FIG. 5.
July 31, 2011 and 2013 PO43−−P profiles for 5, 35, and 55 m outflows.
FIG. 6.
FIG. 6.
July 31, 2011 and 2013 TN profiles for 5, 35, and 55 m outflows. TN, total nitrogen.
FIG. 7.
FIG. 7.
July 31, 2011 and 2013 NO3−−N profiles for 5, 35, and 55 m outflows.
FIG. 8.
FIG. 8.
July 31, 2011 and 2013 NH4+−N profiles for 5, 35, and 55 m outflows.
FIG. 9.
FIG. 9.
September 17, 2011 DO profiles for 5, 35, and 55 m outflows during peak hypoxic conditions.
FIG. 10.
FIG. 10.
July 24, 2011 NO3−−N profiles for 5, 35, and 55 m outflows during hypoxic conditions.
FIG. 11.
FIG. 11.
August 29, 2011 PO43−−P profiles for 5, 35, and 55 m outflows during hypoxic conditions.
FIG. 12.
FIG. 12.
July 24, 2013 DO profiles for 5, 35, and 55 m outflows during hypoxic conditions.
FIG. 13.
FIG. 13.
August 29, 2013 DO profiles for 5, 35, and 55 m outflows during hypoxic conditions.
FIG. 14.
FIG. 14.
July 24, 2013 PO43−−P profiles for 5, 35, and 55 m outflows during hypoxic conditions.
See this image and copyright information in PMC

References

    1. Abirhire O., North R.L., Hunter K., Vandergucht D.M., Sereda J., and Hudson J.J. (2015). Environmental factors influencing phytoplankton communities in Lake Diefenbaker, Saskatchewan, Canada. J. Great Lakes Res. 41, 118
    1. Ashmore P., and Day T. (1988). Spatial and temporal patterns of suspended-sediment yield in the Saskatchewan River basin. Can. J. Earth Sci. 25, 1450
    1. Bucak T., Trolle D., Tavşanoğlu, Ü.N., Çakıroğlu, A.İ., Özen A., Jeppesen E., and Beklioğlu M. (2018). Modeling the effects of climatic and land use changes on phytoplankton and water quality of the largest Turkish freshwater lake: Lake Beyşehir. Sci. Total Environ. 621, 802. - PubMed
    1. Çalişkan A., and Elçi S. (2009). Effects of selective withdrawal on hydrodynamics of a stratified reservoir. Water Resour. Manage. 23, 1257
    1. Carr M., Li L., Sadeghian A., Phillips I., and Lindenschmidt K.-E. (2019). Modelling the possible impacts of climate change on the thermal regime and macroinvertebrate community of a regulated prairie river. Ecohydrology e2102

LinkOut - more resources