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2015 URBAN WATER MANAGEMENT PLAN <br />Constituents of Emerging Concern (CEC) — CECs are either synthetic or naturally occurring <br />substances that are not currently regulated in water supplies or wastewater discharged but can be <br />detected using very sensitive analytical techniques. The newest group of CECs include <br />pharmaceuticals, personal care products, and endocrine disruptors. OCWD's laboratory is one of a <br />few in the state of California that continuously develops capabilities to analyze for new compounds <br />(OCWD, Groundwater Management Plan 2015 Update, June 2015). <br />16.2.4 Climate Change <br />Changing climate patterns are expected to shift precipitation patterns and affect water supply. <br />Unpredictable weather patterns will make water supply planning more challenging. The areas of concern <br />for California include a reduction in Sierra Nevada Mountain snowpack, increased intensity and frequency <br />of extreme weather events, and rising sea levels causing increased risk of Delta levee failure, seawater <br />intrusion of coastal groundwater basins, and potential cutbacks on the SWP and CVP. The major impact <br />in California is that without additional surface storage, the earlier and heavier runoff (rather than <br />snowpack retaining water in storage in the mountains), will result in more water being lost to the oceans. <br />A heavy emphases on storage is needed in the State of California. <br />In addition, the Colorado River Basin supplies have been inconsistent since about the year 2000, <br />resulting in 13 of the last 16 years of the upper basin runoff being below normal. Climate models are <br />predicting a continuation of this pattern whereby hotter and drier weather conditions will result in <br />continuing lower runoff. <br />Legal, environmental, and water quality issues may have impacts on Metropolitan supplies. It is felt, <br />however, that climatic factors would have more of an impact than legal, water quality, and environmental <br />factors. Climatic conditions have been projected based on historical patterns but severe pattern changes <br />are still a possibility in the future. <br />3.6.3 Normal -Year Reliability Comparison <br />The water demand forecasting model developed for the OC Reliability Study (described in Section 2.4.1), <br />to project the 25 -year demand for Orange County water agencies, also isolated the impacts that weather <br />and future climate can have on water demand through the use of a statistical model. The explanatory <br />variables of population, temperature, precipitation, unemployment rate, drought restrictions, and <br />conservation measures were used to create the statistical model. The impacts of hot/dry weather <br />condition are reflected as a percentage increase in water demands from the average condition. The <br />average (normal) demand is represented by the average water demand of 1990 to 2014 (CDM Smith, <br />Final Technical Memorandum #1 of Orange County Reliability Study, April 2016). <br />The City is 100 percent reliable for normal year demands from 2020 through 2040. The City has <br />entitlements to receive imported water from Metropolitan via the regional distribution system. Although <br />pipeline and connection capacity rights do not guarantee the availability of water, per se, they do <br />guarantee the ability to convey water when it is available to the Metropolitan distribution system. All <br />imported water supplies are assumed available to the City from existing water transmission facilities. The <br />demand and supplies listed below also include local groundwater supplies that are available to the City <br />through OCWD by a pre- determined pumping percentage. <br />arcadis.mni <br />M 'U� 3 -19 <br />M <br />