Robust Assessment of Adaptation Options for the Hetch Hetchy Regional Water System in the Face of Climate and Tectonic Risks
Abstract
Recent drought episodes and the memory of the severe droughts of the past cause the San Francisco Public Utilities Commission (SFPUC) to fear the possible impacts of a changing climate. At the same time, the risk of a major earthquake along the San Andreas Fault is also paramount concern for SFPUC since a water utility must persevere through such short term shocks as well. The question for SFPUC and similar urban water utilities around the country is how to maintain system resilience in the face of both climate and tectonic deep uncertainty. To answer this question requires a new analysis approach never before attempted for urban water planning. We introduce Freshwater Resilience by Design, a planning approach that addresses long-term uncertainties such as climate and demand changes with short-term shocks such as earthquakes in a single conceptual framework. To implement the approach, we created the San Francisco Water System Model (SFWSM) to optimize operations of the major facilities under the various Hetch Hetchy Regional Water System's constraints using a linear programming solver at daily time step. The Hetch Hetchy Regional Water System is a complex system operated by the SFPUC to supply drinking water to San Francisco city, 26 wholescale customers and 10 retail customers. SFPUC must also comply with instream flow requirements downstream of the major infrastructure and ensure water deliveries to Modesto and Turlock Irrigation Districts, who have prior rights for water from the Tuolumne River. We further used SFWSM to assess the vulnerability of the current Hetch Hetchy Regional Water System under climate and tectonic risks using the Decision Scaling approach. Structural and non-structural adaptation options are discussed to reduce vulnerability and increase resilience of the SFPUC's infrastructure.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H21G..04F
- Keywords:
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- 1807 Climate impacts;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY;
- 1918 Decision analysis;
- INFORMATICS;
- 6309 Decision making under uncertainty;
- POLICY SCIENCES & PUBLIC ISSUES