The Bugflow Experiment

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Example bugflows hydrograph

What is the “bug flow experiment? This would be an experimental release at Glen Canyon Dam to see if short-duration steady flow might increase the diversity and production of aquatic insects below Glen Canyon Dam. This experiment is included in the Preferred Alternative of the LTEMP DEIS. These “bug flows” would occur from May to August and would maintain releases on the weekends to a level equal to the minimum release made during the week. This would allow aquatic insects two days a week throughout the river corridor to be able to lay their eggs at a stage where they would not be at risk of being dewatered or desiccated. The experiment would include monitoring to evaluate if the flows did increase the diversity and production of aquatic insects. The experiment was designed to test the hypothesis put forward in Kennedy's 2016 BioScience Paper while minimizing impacts to the hydropower resource at Glen Canyon Dam by having the steady flows on the weekend. This results in a transfer of water from the weekend to the weekdays increasing the daily minimums and maximums and the range of fluctuation during the week. Western believes that this experiment will result in only a small decrease in the energy value, but a modest increase in the capacity value of hydropower produced at Glen Canyon Dam.

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Updates Modeling Assumptions: Bug flows would occur every weekend from May - Aug (34 days, we scheduled July to have the 5th weekend because that how it works out in 2016) Weekend flow = minimum flow for the month = weekday minimum flow (see weekly hydrographs on the monthly tabs) Hybrid Public Draft monthly volume, ramp rates, or daily change parameters Moved weekend water to weekday releases Energy prices used in this modeling are for a Saturday, Sunday, and a weekday for May, June, July, and August 2016. These are the energy prices Argonne used in the LTEMP modeling for 2016. Hybrid Public Draft 8.23 MAF volumes: May = 632 June = 663 July = 749 August = 800 Ramp rates: 4,000 up and 2,500 down Daily change: May = 9 June = 10 July = 10 August = 10 Minimum release: 5,000 cfs Maximum release: 25,000 cfs

Information and Links Food Base Page LTEMP Experimental Action: Aquatic Resource-Related Experimental Treatments (BA, pages 30-41) [1] Low steady weekend flows (“bug flows”) would be conducted to test whether the flows would increase insect abundance. On an experimental basis, for example, flows would be held low and steady for two days per week (weekends) from May through August to attempt to improve the productivity of the aquatic food base, and increase the diversity and abundance of mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera), which are collectively referred to as EPT. Papers and Presentations Kennedy et al. 2016. Flow Management for Hydropower Extirpates Aquatic Insects, Undermining River Food Webs. BioScience Other Stuff