Phosphorus Distribution in Delta Sediments: A Unique Data Set from Deer Creek Reservoir

Abstract

Recently, Deer Creek Reservoir (DCR) underwent a large drawdown to support dam reconstruction. This event exposed sediments inundated by the reservoir, since dam completion in the early 1940s. This event allowed us to take sediment data samples and evaluate them for phosphorous (P) content. It is difficult for normal reservoir sediment studies to have sediment samples at high spatial resolution because of access. During the drawdown, we collected 91 samples on a grid 100 m in one direction and 200 m in the other. This grid defined an area of approximately 750,000 m2 (185 acre). We took both surface samples, and at some sites, vertical samples. We determined water soluble P for all the samples, and P in four other reservoirs or fractions for 19 samples. Results showed water soluble P in the range of 2.28 × 10−3 to 9.81 × 10−3, KCl-P from 2.53 × 10−3 to 1.10 × 10−2, NaOH-P from 5.30 × 10−2 to 4.60 × 10−1, HCl-P from 1.28 × 10−1 to 1.34, and residual (mostly organic) P from 8.23 × 10−1 to 3.23 mg/g. We provide this data set to the community to support and encourage research in this area. We hope this data set will be used and analyzed to support other research efforts.

Method for Estimating Sediment Mass Movement from Delta Recutting: A Case Study Using Single Beam Sonar in Deer Creek Reservoir

“…We determined water soluble P for all 91 samples, and P in four other reservoirs or fractions for 19 samples. Results showed water soluble P in the range of 2.28 × 10 −3 to 9.81 × 10 −3 , KCl-P from 2.53 × 10 −3 to 1.10 × 10 −2 , NaOH-P from 5.30 × 10 −2 to 4.60 × 10 −1 , HCl-P from 1.28 × 10 −1 to 1.34, and residual (mostly organic) P from 8.23 × 10 −1 to 3.23 mg/g [5]. Figure 2 shows the sediment delta during samples.…”

“…The suspended sediment have a profound effect on aquatic ecosystems [34]. Resuspension can introduce trapped nutrients into the water column, promoting the growth of algae and other aquatic organisms, adversely affecting water quality [5,33,35].…”

“…Increased nutrient loads during this time period can have higher impacts on algal blooms than loads during other times of the year. There have been many studies on sediment movement and the effect it has on water quality [2,5,35,36]. These studies document various methods to monitor and quantify sediment movement along with impacts from these processes.…”

“…Studies conducted in reservoirs which reduced external inputs of nutrients have shown, that in some areas, external reduction had limited effect on eutrophication [3,4]. Excessive amounts of nutrients may increase productivity in ecosystems, leading to problems with water quality [5,6]. In addition to nutrients, bottom sediments can accumulate pollutants.…”

“…The recutting and resuspension of sediments can mobilize these nutrients and pollutants and these physical processes are important mechanisms that control nutrient and pollutant concentrations in aquatic environments [2]. Understanding and quantifying these sediment mobilization processes in reservoirs will allow researchers to adequately maintain a sustainable source of water [5,6].…”