4b: Upper Dam Project Update — original pdf

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M E M O R A N D U M Joint Committee of the Environmental Commission & Parks and Recreation Board Michael P. Kelly, P.E., Managing Engineer Environmental Resource Management, Watershed Protection Department January 16, 2020 TO: FROM: DATE: SUBJECT: Joint Committee of the Environmental Commission & Parks and Recreation Board, Item 4b, Upper Dam Project Update In response to discussions at the October 16, 2019 Joint Committee meeting on the Barton Springs Pool Upper Dam proposal, staff has the following update. Staff presented a proposal to install three gates into the upper dam that would allow periodic inflows of Barton Creek water into Barton Springs Pool. Public testimony on the proposal included the following categories of concern: Increases in pollutant concentration, risk to human health; Increases in algae; • Changes to temperature; • • • Certainty of gate operations; • Costs/benefits and • Certainty of ecological benefits. Staff from Watershed Protection and Parks and Recreation appreciate this first round of stakeholder input. The concerns raised by the public echo questions posed by staff in developing a plan to further investigate the feasibility of this proposal. After examining the existing data and information and determining what is needed to make conclusive projections regarding the performance of the gates, staff decided that we are unable at this time to recommend moving forward with the next phase of the gate project. In order to move forward, staff needs to gain a more complete understanding of the pool ecosystem that will allow us to define a desired condition warranting the investments in a gate system. That understanding requires more information on historical and baseline conditions in the pool. It also requires that we develop a more comprehensive model of the pool system that will allow staff to manipulate the inflow variables to calculate impacts on temperature, pollution concentration, impact on pool cleaning and gate operations. To that end, staff will develop a workplan for consideration in Fiscal Year 2021 that outlines all the needed steps to develop a more complete understanding of the pool. Should this plan rise to high priority as a department activity, staff will include in our project list for Fiscal Year 2021. At that time, we will be able to provide an updated briefing on potential next steps.  Should the Joint Committee members have any follow up questions, please contact Mike Kelly at 512- 974-6591 or mike.kelly@austintexas.gov. cc: Jorge Morales, Director, Watershed Protection Department Mike Personett, Assistant Director, Watershed Protection Department Kimberly McNeeley, Director, Parks and Recreation Department Liana Kallivoka, Assistant Director, Parks and Recreation Department Anthony Segura, Assistant Director, Parks and Recreation Department Jodi Jay, Aquatics Division Manager, Parks and Recreation Department David Johns, Section Manager, Watershed Protection Department