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Discrete depth profiles of temperature, dissolved oxygen, oxidation-reduction potential, conductivity, specific conductance, and pH were collected with various handheld YSI water quality probes and discrete depth profiles of photosynthetic active radiation (PAR) were collected with a LI-COR underwater light meter from 2013 to 2022 in five drinking water reservoirs in southwestern Virginia, USA. Secchi disk depth data complement the PAR data to estimate water transparency. All YSI and PAR depth profiles were collected on approximately 1-meter intervals. These reservoirs are: Beaverdam Reservoir (Vinton, Virginia), Carvins Cove Reservoir (Roanoke, Virginia), Falling Creek Reservoir (Vinton, Virginia), Gatewood Reservoir (Pulaski, Virginia), and Spring Hollow Reservoir (Salem, Virginia). Beaverdam, Carvins Cove, Falling Creek, and Spring Hollow Reservoirs are owned and operated by the Western Virginia Water Authority as primary or secondary drinking water sources for Roanoke, Virginia, and Gatewood Reservoir is a drinking water source for the Town of Pulaski, Virginia. The data package consists of two datasets: 1) YSI and PAR profiles; and 2) Secchi depth data. The YSI and PAR depth profiles and Secchi depths were measured at the deepest site of each reservoir adjacent to the dam and other in-reservoir transects. YSI measurements were also collected at a gauged weir on the primary inflow tributary at Falling Creek, other inflows and outflows at Falling Creek, inflows and outflows at Beaverdam, and inflows at Carvins Cove. In 2021, YSI profiles were also collected from a littoral site in Beaverdam. Data were collected approximately fortnightly in the spring months (March - May), weekly in the summer and early autumn (June - September), and monthly in the late autumn and winter (October - February) in Falling Creek and Beaverdam Reservoirs; data coverage in the other three reservoirs varies among years.
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River management response to multi‐decade changes in timing of reservoir inflows, Columbia River Basin, USA
Abstract Around the world, long‐term changes in the timing and magnitude of streamflow are testing the ability of large managed water resource systems constructed in the 20th century to continue to meet objectives in the 21st century. Streamflow records for unregulated rivers upstream of reservoirs can be combined with records downstream of reservoirs using a paired‐watershed framework and concepts of water resource system performance to assess how reservoir management has responded to long‐term change. Using publicly available data, this study quantified how the intra‐annual timing of inflows and outflows of 25 major reservoirs has shifted, how management has responded, and how this has influenced reliability and vulnerability of the water resource system in the 668,000 km2Columbia River basin from 1950 to 2012. Reservoir inflows increased slightly in early spring and declined in late spring to early fall, but reservoir outflows increased in late summer from 1950 to 2012. Average inflows to reservoirs in the low flow period exceeded outflows in the1950s, but inflows are now less than outflows. Reservoirs have increased hedging, that is, they have stored more water during the spring, in order to meet the widening gap between inflows and outflows during the summer low flow period. For a given level of reliability (the fraction of time flow targets were met), vulnerability (the maximum departure from the flow target) was greater during periods with lower than average inflows. Thus, the water management system in this large river basin has adjusted to multi‐decade trends of declining inflows, but vulnerability, that is, the potential for excess releases in spring and shortfalls in summer, has increased. This study demonstrates the value of combining publicly available historical data on streamflow with concepts from paired‐watershed analyses and metrics of water resource performance to detect, evaluate, and manage water resource systems in large river basins.
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- Award ID(s):
- 2025755
- PAR ID:
- 10448930
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Hydrological Processes
- Volume:
- 34
- Issue:
- 25
- ISSN:
- 0885-6087
- Page Range / eLocation ID:
- p. 4814-4830
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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