Upload
rylee-whitehead
View
33
Download
0
Embed Size (px)
DESCRIPTION
BRS Seminar Program. Science & Conflicts over Water in the Lower Balonne Peter Cullen Visiting Fellow, BRS. N. Condamine-Balonne Basin. MARANOA RIVER. CONDAMINE RIVER. ST.GEORGE. BALONNE R. LOWER BALONNE FLOODPLAIN. CULGOA R. BALONNE MINOR R. BRIARIE CK. DIRRANBANDI. BALLANDOOL R. - PowerPoint PPT Presentation
Citation preview
BRS Seminar Program
Science & Conflicts over Water in the Lower
Balonne
Peter Cullen
Visiting Fellow, BRS
0 20KM
QLD
NSW
BALONNE R.
CULGOA R.
NARRAN R.
BOKHARA R.
BRIARIE CK
BALLANDOOL R.
BALONNE MINOR R.
ST.GEORGE
HEBEL
DIRRANBANDI
LOWER BALONNEFLOODPLAIN
CONDAMINE RIVER
N
Condamine-Balonne Basin
MARANOA RIVER
Flow thresholdsFlow ML/D Av Return Ecol Sig
25,000 ~ 1.6 years Water moves out of main channel
45,000 ~ 3 years 3 vegetation types 50 % wet
60,000 ~ 3.6 years Main flow paths full 70,000 ~ 4 years At least 40 % of
floodplain wet.120,000 ~ 8 years 70 % of floodplain
wet
Harvesting of Floodflow Water
• Bunds to divert floodflow• Pump from river & distributary
channels• Large, shallow on farm storages• Irrigated cotton• Major economic benefits
Pressures• Huge wealth from cotton• Seen as most over developed
part of MDB• Degradation of river health• Salinity risks• Inadequate payments for water• Pressures on Qld re cap on MDB• Threat to NCC payments• History of court action
The issues
• View that water in LB is over-committed
• LB river system degraded• Anger that irrigators don’t pay
much for water• What should be done?• All science contestable -
Smartrivers
The Cubbie Option
• Proposed 53% of MAF to environment rather than 47% as present
• Premier Beattie proposed acquisition of largest cotton property
• Local outrage - no action needed, & if needed any pain should be spread!
• Beattie proposed independent scientific review
Terms of reference
• Review DNRM IQQM for LB.• Review ecological condition of the
LB, including floodplains & wetlands.• Propose an ecological definition of
healthy working river.• Review likely future ecological
conditions in LB• Review reversibility of likely impacts• Advise on monitoring
Review process
• Cullen, Mein & Marchant• Advertised & invited call for
submissions• Community Reference Group
established (Boully as chair)• Held series of hearings where
submissions put & questions asked
The water conflicts• interests - large financial
benefits to growers & community• values - wetland & river health
issues• data - is the river degraded &
what should be done• structural - DNRM, MDBC, NCC &
irrigators in conflict• labelling - greenies, rapers etc
The data conflicts- Irrigators
• flow measurement underestimates flood flows
• probably already at 53%• IQQM modelling unreliable• river not degraded at all• Irrigators wanted to be clear as
to the environmental assets & what they needed
The Flow Findings
• IQQM modelling & flow measurement adequate for purposes
• Workshops with irrigators reduced concerns about IQQM
• Emphasis on MAF a diversion - focussed on stream gauging errors
• Don’t expect better than +/- 30% in floods
Mean Annual Flow ?
• We know the lowest flow is zero• We don’t know max flow - only
80 yrs records ( need 250 yrs to be 90% sure)
• MAF a nonsense - not a useful management concept in such systems
The Ecological Assets
• Rivers & distributary channels• Coolabah floodplain National
Parks• Narran lakes• Darling river
The challenge of ecological
assessment• LB not yet seen the impacts of
current infrastructure - built in last couple of years
• Lag times for ecological impacts to be obvious - 70 yrs for some wetlands and they are still changing
Rivers & distributary
channels• good woody debris• riparian improved with move
from grazing• weirs block fish in low flow but
not floods• pulses of flow• all storage’s are off-river
Rivers & distributary channels
Invertebrate data• Initial TAP reported
degradation• Subsequent work did not
support• no real downstream trends• similar to adjacent
undeveloped catchments
Rivers & distributary channels
Fish data• no significant downstream
trends• if a subtle trend, problem of
causality - flow or distributary system
• similar fish to adjacent undeveloped catchments
Rivers & distributary channels
• currently in reasonably healthy state with regard to invertebrates and fish
• delighted irrigators and did not please Govt
• based on reasonable sampling• are these good indicators in
ephemeral systems?
Coolabah floodplain National Parks
• limited information submitted• responsible agencies seem to
manage in data free way• Irrigators hardly influence the big
flood - every 10 yrs• Expect Coolabah to cope, but red
gums may go• Reduction in downstream pastoral
production
Darling river• Upper Darling degraded -
several studies• LB may contribute about 20% of
flow• No submissions from NSW or
MDBC on this• LB contributes about 1% of flow
at Murray mouth
Narran lakes
• Ramsar wetland and important bird breeding area
• Used to flood every 2 yrs on average
• Irrigation development will let it flood every 7 yrs
• Currently in good condition but strong view they would not survive likely wetting regime
Narran lakes
• major study by CRC for Freshwater Ecology just starting
• Interim wetting to be every 3.5 yrs• Irrigators to work with Dept
modellers and find least impact way of delivering this
• A share of medium floods• No impact on small floods
Community Reference Group
• Irrigators, business, grazing and green groups
• listened to major presentations• allowed to ask questions• most hearings allowed wider
public to attend• had to report to Govt on our
process
Community Reference Group
• helped focus on important issues• a great learning experience as
they observed our cross-examination of science submissions
• saw themselves as vehicles for a variety of viewpoints rather than presenting a unified community view
Agency science
• Boxes of reports• Consultant after consultant• Series of trivial, short studies
rather than a serious effort• Little integration of knowledge• Little discrimination as to what
we needed to do our job
Agency science• Must not protect from normal
quality assurance procedures of publishing
• If time tight, need independent peer review
• Management domination of science?
• Timeliness of science - setting strategic work priorities