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MANAGING WATER QUANTITY AT ALLOCATION LIMITS Freshwater Management Forum 2013 Professor Bryan Jenkins Waterways Centre: University of Canterbury and Lincoln University. PRESENTATION COVERAGE. Major Issues around Over-Allocation Examples of Claw-back Strategies

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MANAGING WATER QUANTITY AT ALLOCATION LIMITS

Freshwater Management Forum 2013

Professor Bryan Jenkins

Waterways Centre: University of Canterbury and Lincoln University


PRESENTATION COVERAGE

  • Major Issues around Over-Allocation

  • Examples of Claw-back Strategies

  • Adaptive Management Approaches

  • Mitigating Effects on Existing Users

  • Exchange Mechanisms and Incentives


WATER ALLOCATION BASED ON RMA sec 5

  • Enabling resource use for social, economic and cultural well being, while

  • sustaining resource for use of future generations

  • safeguarding life supporting capacity

  • avoiding, remedying or mitigating adverse effects

  • Main over-allocation concerns

  • replenishment of aquifers

  • ecological flows in rivers

  • water quality effects of water use

  • reliability of supply for existing users


PAREORA: EXAMPLE OF CLAW-BACK

  • Foothill River South Canterbury

  • irrigation

  • town supply

  • industry


ALLOCATION LIMITS SET BY CATCHMENT BOARD

  • Total consented allocation

  • - 940 l/s (142% of 7D MALF c.f. interim limit 30%)

  • Minimum flow

  • - 300 l/s (45% of 7D MALF c.f. interim limit 90%)

  • Notes:

  • Mean Annual Low Flow (7 day): lowest flow over 7 consecutive days in a year; average of annual values over data record (660 l/s for Pareora River)

  • Interim Limits: from Proposed NES for ecological flows


OUTCOME OF COLLABORATIVE AND RMA PROCESSES

  • “A Block” Allocation

  • - 198 l/s (30% MALF)

  • Minimum flows next 5 years (Dec-Sep)

  • - 50% restriction at 400 l/s

  • - total cessation at 300 l/s

  • Minimum flows after 5 years (Dec-Sep)

  • - 50% restriction at 470 l/s

  • - total cessation at 400 l/s

  • Minimum flow for A Block holders to take to storage

  • - 1600 l/s

  • Establish B Block allocation

  • - 2500 l/s at minimum flow of 5000 l/s


BALANCING WATER PROTECTION AND ECONOMIC DEVELOPMENT

  • Involve those affected in a collaborative process

  • Give the outcome of that process statutory backing

  • Allow time for transition to increased water protection

  • Provide water at higher river flows for storage to offset loss on run-of-river allocation

  • Existing users get access to higher flows ahead of new applicants


RAKAIA SELWYN LIMITS

  • Rapid growth in use of groundwater

  • Sustainability limit exceeded

  • Drop in groundwater levels and spring-fed streams

First order limit 208 Mm³


Adding controls for cumulative effects to interference controls
ADDING CONTROLS FOR CUMULATIVE EFFECTS TO INTERFERENCE CONTROLS

Restorative Programme for Lowland Streams

  • Annual limits on consents in fully allocated zones

  • Metering of groundwater wells

  • Restrictions on wells with hydraulic connection to lowland streams

  • Ability to vary limits based on water in groundwater system


GROUNDWATER ALLOCATION AND ADAPTIVE MANAGEMENT CONTROLS

  • Current groundwater allocation

  • - annual consented volume based on volume needed in a dry year (1 in 5 year drought): not needed 4 years out of 5

  • - instantaneous volume (rate of pumping) limited by interference effects on neighbouring bores

  • - zone allocation limits based on average use and past irrigation practices to protect groundwater levels and flows in groundwater-fed streams


ANTECEDENT RECHARGE PROPOSAL CONTROLS

  • At full allocation in a period of low recharge it is not possible to:

  • - provide consented volumes, and

  • - maintain flows in groundwater-fed streams

  • Adaptive alternative: relate allocation to antecedent recharge:

  • - base entitlement as fixed percentage of consented annual allocation

  • - adaptive entitlement as variable amount based on recent recharge history


Simulation of antecedent recharge allocation 1960 2009
SIMULATION OF ANTECEDENT RECHARGE ALLOCATION 1960-2009 CONTROLS

Source: Williams et al 2008


Te ngawai river
TE NGAWAI RIVER CONTROLS

  • Foothill river in

    South Canterbury

  • Natural flow falls below

    minimum flow

  • River goes on restriction

  • Incentive for individual users to get as much as possible as soon as possible


COLLABORATIVE GOVERNANCE TRIAL CONTROLS

  • Water User Group of

  • irrigators established

  • Real time measurement of

  • irrigation takes and river flow

  • Results telemetered to internet site so farmers knew total take, their take and river flow

  • Voluntary adjustments by irrigators to maintain flow above restriction levels for as long as possible


MITIGATION OF EFFECTS ON EXISTING USERS CONTROLS

  • Creation of priority bands for existing users to help retain reliability of supply

  • Provision of storage to complement run-of-river or groundwater supply

  • Increased water use efficiency so that less water is needed for same level of production

  • Establishment of exchange mechanisms to facilitate water transfers


WAIMAKARIRI RIVER ALLOCATION CONTROLS

  • “A” Block allocation of 22 cumecs with minimum flow of 46 cumecs

  • Application from Central Plains Water for 25 cumecs

  • If Central Plains given same status as existing users then significant reduction in reliability

  • New flow allocation

  • - AA 5 cumecs community and stock water

  • - A 17 cumecs: minimum flow 46 cumecs

  • - B 27 cumecs: minimum flow 68 cumecs (1:1 sharing)


INCREASE WATER AVAILABILITY THROUGH STORAGE CONTROLS

  • Much of surface water irrigation supply is run-of-river

  • When peak demand exceeds available river flow then irrigation restricted

  • Annual water availability sufficient to meet annual demand but requires storage

  • Concerns about sustainability of storage schemes in relation to river systems

  • Consideration of:

  • - diversion to tributary storage (Waitohi)

  • - off-river storage (Rangitata South)

  • - aquifer recharge (Central Plains)

  • - on-farm storage (Canterbury Plains)


INCREASED WATER USE EFFICIENCY CONTROLS

  • More efficient irrigation methods

  • - match irrigation application to times of and degree of soil moisture deficit

  • Lower irrigation application rates

  • - reduce leakage from macropore flow

  • Improve reliability of supply

  • - ‘just in time’ rather than ‘just in case’

  • Use piped distribution rather than open channels

  • - water savings, reduced on-farm pumping

  • Redistribution of irrigation source

  • - enhance recharge by using surface water in upper catchment and groundwater in lower catchment


EXCHANGE MECHANISMS CONTROLS

  • Collaborative agreements

  • - Te Ngawai water user group

  • Transfers under RMA

  • - problem of consenting

  • Cap and trade

  • - Murray Darling basin; Lake Taupo nitrates

  • Brokerage

  • - concept in CWMS


Water markets in murray darling basin
WATER MARKETS IN MURRAY DARLING BASIN CONTROLS

  • Cap on diversions in 1994: property rights in water created

  • Increase in value of entitlements and increase in irrigator wealth

  • In the “long dry”

    - allocations insufficient to keep all valuable permanent plantings in production but enabled non-producers to sell allocation

    - increased downstream salinity such that irrigators could not use water but able to sell allocation

Source: Young, 2011


Result of diversion cap and trading
RESULT OF DIVERSION CAP AND TRADING CONTROLS

  • Increased water use efficiency reduced return flows

  • Increased capture of overland flows

  • Sale of end-of-season storage

  • Over allocation problems worsened

  • River Murray stopped flowing in 2002

  • Cap should have been on nett use rather than diversion

  • Need incentives to carry forward unused stored water

  • 1500 GL of cap equivalent needed to restore health


Commonwealth interventions
COMMONWEALTH INTERVENTIONS CONTROLS

  • 500 GL secured for environment (2004-9)

  • Additional commitment for $3.1 b purchase of water entitlements

  • Investment in irrigation efficiency $5.8 b

  • Taxpayer cost ($8.9 b) for 15,120 irrigators ($588,000 per irrigator)

  • Subsidised investment worked to disadvantage to those farmers who had paid for their improvements


Lake taupo approach
LAKE TAUPO APPROACH CONTROLS

  • Target: reduce nitrogen load by 20% to bring lake back to 1990 levels

  • Farms occupy 18% of land but contribute more than 90% of the manageable nitrogen

  • Market for nitrogen: farmers and Lake Taupo Protection Trust

  • Farmer can either reduce nitrogen load or purchase nitrogen discharge allowance

  • Trust has $81.5m fund and will stand in the market to purchase nitrogen discharge allowances and/or farmland


Predicted n load for lake taupo from all northern and western streams and seeps

Map of modelled Mean Transit Time of the water from land to lake in western lake catchment

Predicted N load for Lake Taupo from all northern and western streams and seeps

Lake

Taupo

M.A. Gusyev, M. Toews, U. Morgenstern, M. Stewart and J. Hadfield (submitted). Calibration of a transient tritium transport model to tritium time series data from rivers and streams in the western Lake Taupo catchment, New Zealand. Hydrol. Earth Syst. Sci, (submitted) MS No.: hess-2012-318


CONCEPT OF BROKERAGE lake in western lake catchment

  • Providing incentives for existing users to improve water use efficiency and land use practices affecting water quality

  • - linking efficiency requirements to access to reliable water from storage

  • - inefficient or unproductive water to be bought out and water re-allocated for environmental or productive purposes

  • - third party investment in efficiency gains in exchange for water savings


MANAGING AT AVAILABILITY LIMITS lake in western lake catchment

  • Issues: aquifer replenishment, ecological flows, water quality effects, supply reliability

  • Approaches: involvement, statutory backing, time to adjust, alternative access

  • Adaptive Management: incorporate natural variability, integrated measurement

  • Existing Users: priority bands, storage, improved efficiency, exchange mechanisms

  • Exchange mechanisms: collaborative governance, transfers, cap and trade (?), brokerage


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