Turning Routine Data into Systems Insight: Multivariate Analysis of Water Quality Dynamics in a Major Drinking Water Reservoir

Background Riparian corridors can affect nutrient, organic matter, and sediment transport, all of which shape water quality in streams and connected downstream waters. When functioning riparian corridors remain intact, they provide highly valued water quality ecosystem services. However, in rapidly urbanizing watersheds, riparian corridors are susceptible to development modifications that adversely affect those ecosystem services. Protecting high quality riparian corridors or restoring low quality corridors are widely advocated as watershed level water quality management options for protecting those ecosystem services. The two approaches, protection or restoration, should be viewed as complementary by watershed managers and provide a foundation for targeting highly functioning riparian corridors for protection or for identifying poorly functioning corridors for restoration. Ascertaining which strategy to use is often motivated by a specific ecosystem service, for example water quality, upon which watershed management is focused. We have previously reported on a spatially explicit model that focused on identifying riparian corridors that have specific characteristics that make them well suited for purposes of preservation and protection focused on water quality. Here we hypothesize that focusing on restoration, rather than protection, can be the basis for developing a watershed level strategy for improving water quality in urbanizing watersheds. Methods The model described here represents a geographic information system (GIS) based approach that utilizes riparian characteristics extracted from 40-meter wide corridors centered on streams and rivers. The model focuses on drinking water reservoir watersheds that can be analyzed at the sub-watershed level. Sub-watershed riparian data (vegetation, soil erodibility and surface slope) are scaled and weighted based on watershed management theories for water quality, and riparian restoration scores are assigned. Those scores are used to rank order riparian zones –the lower the score the higher the priority for riparian restoration. Results The model was applied to 90 sub-watersheds in the watershed of an important drinking water reservoir in north central Texas, USA. Results from this study area suggest that corridor scores were found to be most correlated to the amount of: forested vegetation, residential land use, soils in the highest erodibility class, and highest surface slope (r2 = 0.92, p < 0.0001). Scores allow watershed managers to rapidly focus on riparian corridors most in need of restoration. A beneficial feature of the model is that it also allows investigation of multiple scenarios of restoration strategies (e.g., revegetation, soil stabilization, flood plain leveling), giving watershed managers a tool to compare and contrast watershed level management plans.

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Occurrence of cyanobacteria, actinomycetes, and geosmin in drinking water reservoir in Korea: a case study from an algal bloom in 2012

Water Science & Technology Water Supply ◽

10.2166/ws.2020.102 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1862-1870

Author(s):

Jung Eun Lee ◽

Seok-Jae Youn ◽

Myeongseop Byeon ◽

Soon-Ju Yu

Keyword(s):

Water Quality ◽

Drinking Water ◽

Cell Density ◽

Algal Bloom ◽

Water Reservoir ◽

Primary Source ◽

High Concentration ◽

Drinking Water Reservoir ◽

Peak Value

Abstract In 2012, a large concentration of geosmin was found in the Paldang reservoir, which is the primary source of drinking water in Seoul, Korea. In June and September 2012, we measured the concentrations of cyanobacteria and actinomycetes, and geosmin, to identify the source of geosmin in the Paldang reservoir. A total of 68 water samples were collected from two sampling sites (Sambong, Paldang), and used to analyze the correlation between cyanobacteria, actinomycetes, and geosmin. The cell density attained a maximum of 24,722 cells/mL on August 11, 2012 and geosmin occurred at a high concentration of 3,934 ng/L on August 13 in Sambong. After July 31, 2012 a rapid increase in growth and cell density occurred with a peak value of 11,568 cells/mL on August 6, 2012. At the same time, the geosmin concentration increased to 3,157 ng/L in Paldang. The number of cyanobacteria positively correlated with geosmin concentration (R2 = 0.84, P < 0.0001), while actinomycetes were not significantly correlated with geosmin (R2 = 0.01, P = 0.709). In addition, the number of actinomycetes was associated with increased turbidity (R = 0.507). Among the various water quality constituents, temperature affected cyanobacteria in the Paldang reservoir (R = 0.803). These results suggest that cyanobacteria are the main source of geosmin in the Paldang reservoir, which might be providing useful information for managing the unpleasant taste of its drinking water.

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Shifts in water quality in a drinking water reservoir during and after the removal of cyprinids

Hydrobiologia ◽

10.1007/s10750-010-0231-x ◽

2010 ◽

Vol 649 (1) ◽

pp. 95-106 ◽

Cited By ~ 5

Author(s):

Tiia Pedusaar ◽

Ilkka Sammalkorpi ◽

Arto Hautala ◽

Jaana Salujõe ◽

Ain Järvalt ◽

...

Keyword(s):

Water Quality ◽

Drinking Water ◽

Water Reservoir ◽

Drinking Water Reservoir

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Seasonal Water Quality and Algal Responses to Monsoon-Mediated Nutrient Enrichment, Flow Regime, Drought, and Flood in a Drinking Water Reservoir

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182010714 ◽

2021 ◽

Vol 18 (20) ◽

pp. 10714

Author(s):

Md Mamun ◽

Usman Atique ◽

Ji Yoon Kim ◽

Kwang-Guk An

Keyword(s):

Water Quality ◽

Drinking Water ◽

Flow Regime ◽

Nutrient Enrichment ◽

Water Reservoir ◽

Reservoir Water ◽

Chl A ◽

Drought And Flood ◽

Drinking Water Reservoir

Freshwater reservoirs are a crucial source of urban drinking water worldwide; thus, long-term evaluations of critical water quality determinants are essential. We conducted this study in a large drinking water reservoir for 11 years (2010–2020). The variabilities of ambient nutrients and total suspended solids (TSS) throughout the seasonal monsoon-mediated flow regime influenced algal chlorophyll (Chl-a) levels. The study determined the role of the monsoon-mediated flow regime on reservoir water chemistry. The reservoir conditions were mesotrophic to eutrophic based on nitrogen (N) and phosphorus (P) concentrations. An occasional total coliform bacteria (TCB) count of 16,000 MPN per 100 mL was recorded in the reservoir, presenting a significant risk of waterborne diseases among children. A Mann–Kendall test identified a consistent increase in water temperature, conductivity, and chemical oxygen demand (COD) over the study period, limiting a sustainable water supply. The drought and flood regime mediated by the monsoon resulted in large heterogeneities in Chl-a, TCB, TSS, and nutrients (N, P), indicating its role as a key regulator of the ecological functioning of the reservoir. The ambient N:P ratio is a reliable predictor of sestonic Chl-a productivity, and the reservoir was P-limited. Total phosphorus (TP) had a strong negative correlation (R2 = 0.59, p < 0.05) with the outflow from the dam, while both the TSS (R2 = 0.50) and Chl-a (R2 = 0.32, p < 0.05) had a strong positive correlation with the outflow. A seasonal trophic state index revealed oligo-mesotrophic conditions, indicating a limited risk of eutrophication and a positive outcome for long-term management. In conclusion, the Asian monsoon largely controlled the flood and drought conditions and manipulated the flow regime. Exceedingly intensive crop farming in the basin may lead to oligotrophic nutrient enrichment. Although the reservoir water quality was good, we strongly recommend stringent action to alleviate sewage, nutrient, and pollutant inflows to the reservoir.

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Spatial and Temporal Variations of Water Quality and Trophic Status in Xili Reservoir: a Subtropics Drinking Water Reservoir of Southeast China

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/100/1/012183 ◽

2017 ◽

Vol 100 ◽

pp. 012183

Author(s):

Song Yunlong ◽

Jinsong Zhang ◽

Jia Zhu ◽

Wang Li ◽

Aimin Chang ◽

...

Keyword(s):

Water Quality ◽

Drinking Water ◽

Trophic Status ◽

Water Reservoir ◽

Temporal Variations ◽

Spatial And Temporal Variations ◽

Southeast China ◽

Drinking Water Reservoir

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Water Quality Responses during the Continuous Mixing Process and Informed Management of a Stratified Drinking Water Reservoir

Sustainability ◽

10.3390/su11247106 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7106

Author(s):

Zizhen Zhou ◽

Tinglin Huang ◽

Weijin Gong ◽

Yang Li ◽

Yue Liu ◽

...

Keyword(s):

Water Quality ◽

Drinking Water ◽

Quality Improvement ◽

Microbial Community ◽

Organic Carbon ◽

Water Reservoir ◽

Mixing Process ◽

Water Quality Improvement ◽

Continuous Mixing ◽

Drinking Water Reservoir

Aeration and mixing have been proven as effective in situ water quality improvement methods, particularly for deep drinking water reservoirs. While there is some research on the mechanism of water quality improvement during artificial mixing, the changes to water quality and the microbial community during the subsequent continuous mixing process is little understood. In this study, we investigate the mechanism of water quality improvement during the continuous mixing process in a drinking water reservoir. During this period, we found a reduction in total nitrogen (TN), total phosphorus (TP), ammonium-nitrogen (NH4-N), iron (Fe), manganese (Mn), and total organic carbon (TOC) of 12.5%–30.8%. We also measured reductions of 8.6% and 6.2% in TN and organic carbon (OC), respectively, in surface sediment. Microbial metabolic activity, abundance, and carbon source utilization were also improved. Redundancy analysis indicated that temperature and dissolved oxygen (DO) were key factors affecting changes in the microbial community. With intervention, the water temperature during continuous mixing was 15 °C, and the mixing temperature in the reservoir increased by 5 °C compared with natural mixing. Our research shows that integrating and optimizing the artificial and continuous mixing processes influences energy savings. This research provides a theoretical basis for further advancing treatment optimizations for a drinking water supply.

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