Recent California Water Transfers: Emerging Options in Water Management

Abstract

SUPPLEMENTARY NOTATION COSATI CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP ABSTRACT (Continue on reverse if necessary and identify by block number)Report examines the recent use of water transfers in California. Emphasis is on the use of water transfers during the current drought and how planners and operators of federal, state, and local systems can integrate water transfers into the planning and operations of their systems. Through the California experience, the study identifies motivations for incorporating water transfers into water supply systems, reviews a variety of water transfer types, and discusses the integration of water transfers with traditional supply argumentation and water conservation measures.Limitations, constraints, and difficulties for employing water transfers within existing systems are also discussed. The study focuses primarily on the technical, planning, and operational aspects of water transfers, rather than the legal, economic, and social implications.

Water Banks: What Have We Learnt from the International Experience?

“…The severe drought of 1976-1977 was a crucial moment, driving the Bureau of Reclamation to introduce the first Californian water bank to facilitate water trading between public water entities, especially for urban supply. Over the course of that year, the bank bought 57 Mm 3 (1 Mm 3 = 1 hm 3 = 1 GL = 810.7 acre-feet), of which 52 Mm 3 was subsequently resold [33]. Nevertheless, the main problem facing this first bank was the restriction imposed on private users, which prevented farmers-the main users of water in the state-from accessing the resource [34].…”

Interbasin Water Transfer Practices in Turkey

“…Mean annual precipitation varies from 250 mm to 2500 mm, with a long-term mean annual precipitation of 650 mm ( Figure 1). This is equivalent to 501 km 3 [13]. Gross freshwater potential per capita in Turkey is given in Figure 2.…”

“…Allocation of the water use capacity is as follows: 74% agricultural irrigation, 16% for drinking and municipal uses, and 10% for industrial uses. By 2030, the amount of water used is projected to reach 72 km 3 for agricultural irrigation, 18 km 3 for drinking and municipal uses, and 22 km 3 for industrial uses [14]. Currently, Turkey uses 36% of its net freshwater potential and is ranked in the medium-to-high waterscarce countries.…”

“…Inter or intrabasin water transfers can be defined as transfer of water by a ditch, canal, tunnel or pipeline from its basin of origin for use in another, or from one river to another in order to eliminate water deficit [3][4][5][6]. Water transfers can take many forms such as permanent transfer, contingent transfer/dry year options, spot market transfers, water banks, water wheeling or water exchanges, and transfer of reclaimed, conserved and surplus water.…”

“…The existing total volume of interbasin water transfer is about 490 km 3 . Africa has 20 schemes with a total existing capacity of about 5 km 3 yr -1 .…”