GEOG256 1st Edition Lecture 7 Outline of Last Lecture II Cities and Water Quality III Groundwater vs Surface Water IV Pollution and Runof Outline of Current Lecture II Water Supply III Where Water Comes From IV Issues V Water Conservation Current Lecture Water Supply US Water Withdrawals Power plants 49 Ag 31 Public supply 11 Domestic 1 Industry mines 5 Withdrawal use and return to the source 75 Consumption use without return to the source due to evaporation transpiration incorporation into products or tissue 25 Arizona Water use Agriculture 70 Municipal 33 These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Industrial 8 Where does Arizona s water come from 40 from groundwater 39 Colorado River 19 surface water 2 effluent Overall supply in USA is abundant 4 8 billion acre feet of annually renewable supply 68 billion acre feet stored in lakes and groundwater 380 maf withdrawn annually 100 maf is consumptive use the issue is uneven geographical and temporal distribution The result is local hot spots Not all hotspots are in the southwest and not all where use exceeds supply Pressures will increase due to Population growth and shift to semi arid areas In stream minium flow requirements Global warming Energy production Aging infrastructure Issues with overuse Economic growth housing development Recreation fisheries and habitat Groundwater over drafting landscapes and subsidence Food security and prices Well being doesn t depend on growing use Tucson decoupling Fewer smaller pols Fixtures appliances Shift from turf Smaller lots yards Water Conservation Saving of 20 30 are cost efective based on payback rates Hermes is saving 9 300 euros per ear after spending 3 510 euros to install waterless urinal systems in London s tallest office tower Elements of Xeriscaping Drought tolerant native plants Mulch Drip irrigation Smart water systems Water harvesting Reclaimed water systems Rainwater harvesting Tucson Rainwater harvesting and recycling First in USA 50 of water for landscaping in commercial projects must come from rainwater Largest in USA reclaimed water system Water is underpriced Price should be cost of distribution reservoirs treatment systems opportunity cost habitat recreation etc Prices lie well below this price so we use more A 10 increase would decrease water use by about 6 but it difers by income Pricing is more cost efective than regulations due to rebound efects Incentives Las Vegas pays 1 50 per square foot to convert to desert landscaping 150 million square feet of grass retired 3500 acres 10 UAs 2600 football fields Inclining block rate structure Unit price increases as volume increases a way to reward conservation