Filters: Tags: Willow Creek Lake (X)
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Samples were collected from Willow Creek Lake approximately monthly during May through September by the Nebraska Department of Environmental Quality as a part of the Ambient Lake Monitoring Program since at least 1989. Lake samples were analyzed for several constituents, including nutrients and chlorophyll. Though several different station identification numbers have been used over the course of monitoring, the general location of sampling corresponds to the deep site referenced in Rus and others (2018).
Chemistry data were collected or compiled from stream water, lake water, and groundwater. Stream water samples were collected more frequently to capture the range of streamflow conditions. Discretely collected samples were analyzed for nitrogen content (total Kjeldahl nitrogen and nitrate plus nitrite nitrogen) and phosphorus (total phosphorus and phosphate as phosphorus). A subset of samples were analyzed for nitrogen and oxygen isotopes associated with nitrate and phosphate, respectively, to identify nutrient sources in Willow Creek Lake.
The retention or release of nutrients into the water column from sediment, also known as internal loading, is another source of nutrients to the lake water column. Sediment cores collected from Willow Creek Lake in September 2013 and June 2014 were incubated for 7 days to assess potential for sediment to produce or consume water column phosphorus under aerobic (oxic) and anaerobic (anoxic) conditions using techniques similar to Penn and others (2000); the oxic conditions served as a control and the anoxic conditions represented typical lake sediment environments. Phosphate as phosphorus and total dissolved phosphorus release rates (milligrams phosphorus per square meter per day) were estimated by dividing the change...
The data set contains vertical profiles of physical (water temperature, specific conductance, pH, dissolved oxygen, and turbidity) and biological measurements (chlorophyll-a and phycocyanin) that were measured hourly and then summarized on a daily basis within Willow Creek Lake during the non-winter seasons.
Streamflow was measured at the three largest inflows (the Foster, NT, and ST sites) of Willow Creek Lake and at the outflow of the lake. Flow data were typically available at a 15-minute frequency, but generally were summarized as daily means. Flow data for the Foster, NT, and outflow sites were provided by the Nebraska Department of Natural Resources (NDNR) and were estimated using stage-flow relations applied to measured stage following protocols described by Kennedy (1983). Flow at the ST site was measured by the U.S. Geological Survey using an indirect rating curve with water levels monitored continuously by a submersible pressure transducer and periodic streamflow measurements collected using a Parshall flume...
Flow interaction between Willow Creek Lake and groundwater was calculated from a lake water balance (Healy and others, 2007) in which all of the other flow components were either measured or estimated between 2012 and 2014 (as described in Rus and others, 2018) and the interaction was the residual term. Inflow terms consisted of streamflow at three sites (Foster, NT, and ST) as well as the direct precipitation onto the lake. Measured outflow terms consisted of the streamflow at the outflow site and the direct evaporation from the lake. Increases in lake storage had the same effect on the water balance as an outflow. All components of the water balance were tabulated on a daily basis and converted to units of acre-feet...
A meteorological station was deployed on the dam to measure hourly relative humidity, wind speed and direction, and photosynthetically active radiation between August 3, 2012 and October 30, 2014, with air temperature and solar radiation added on April 30, 2013. Additional meteorological data were obtained from the National Climatic Data Center (2015): Precipitation data were obtained from Pierce, Nebr.; Air temperature, wind speed, and wind direction data were obtained from Norfolk, Nebr., and were used to fill gaps in measured meteorological datasets. These gaps primarily corresponded to the period between the beginning of the furnished data (January 1, 2012) and the onset of measurements on the dam (August 3,...
Daily measurements of Willow Creek Lake water storage were provided by the Nebraska Department of Natural Resources for 2012–14. These water levels were used in conjunction with a table (provided by the Lower Elkhorn Natural Resources District) relating lake storage volume to surface area. From these, daily estimates of surface area were derived for the lake.
Genus-level taxonomic data of the phytoplankton community were collected from Willow Creek Lake near Pierce, Nebraska in 2013–14. Algal cell concentration and biomass data also were recorded.
Monitoring data were collected from the Willow Creek drainage basin and Willow Creek Lake with a focus on 2012-14. Included are datasets of meteorology; lake measurements of water levels, sediment nutrients, and physical, chemical, and biological data; streamflow and stream chemistry; and calculated nutrient loads to the lake.
A variety of nutrient sources transported by multiple flow paths contribute to the nutrient load entering Willow Creek Lake. In addition to Willow Creek, there are several smaller tributaries that contribute streamflow to the lake. As Spalding and others (1992) noted, groundwater interactions with the lake are likely another important contributor to nutrient loading. Nutrient load was computed as the product of volumetric flow rate and nutrient concentration and was applied to both streamflow and groundwater. A water balance approach was used to estimate the volumetric flow rates (hereinafter referred to as flow) for streams and atmospheric sources, with groundwater flow as the residual of that balance. Nutrient...
Categories: Data;
Tags: Willow Creek,
Willow Creek Lake,
harmful algal blooms,
nutrient content (water)
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