Annual Report 2011 - Watercare

Watercare Services Limited
2011 ANNUAL REPORT
Sustainable environment
6A. Percentage performance:
atmospheric CO 2
emissions.
10 20 30 40 50 60 70 80 90 100
2011
75% 7/10
Target 75% reduction on 1990 levels
2007 2008 2009 2010
85 85 85 85
Watercare calculates its greenhouse gas emissions, including carbon dioxide (CO 2
), methane and nitrous oxide that are largely generated from
% % % %
the treatment of wastewater. This year the company achieved a 75% reduction on the greenhouse gas levels emitted in 1990, which is the company’s
historic benchmark for performance in this area. This result appears lower than in previous years because Watercare is now running additional wastewater plants.
6B. Percentage performance against target:
internally sourced energy.
10 20 30 40 50 60 70 80 90 100
2011
7/10 91%
New Performance Measure
Target 35% of energy used
Watercare aims to source 35% of all its energy requirements from internal sources, principally biogas reuse at its two largest wastewater plants, Mangere and
Rosedale, and from five hydro-electric generators within the water supply system. This year, Watercare sourced 32% of its energy, achieving 91% of its target.
6C. Percentage performance: recycling.
Percentage of potential general waste material recycled
10 20 30 40 50 60 70 80 90 100
Staff volunteer for a zero-waste recycling programme and each year the company measures the amount of general waste that was recycled
rather than going to landfill. This year it was estimated that 70% of company waste with the potential for reuse was separated for recycling.
Target
2011
70% 7/10
2007 2008 2009 2010
65 75 75 70
% % % %
6D. Percentage performance against target: waste management.
Solid waste diverted from landfills
10 20 30 40 50 60 70 80 90 100
2011
80% 7/10
New Performance Measure
Target
Watercare operates a programme to recover valuable metals and nutrients that could be reused in the future and to divert as much solid waste
as possible to purpose-built rehabilitation projects rather than send this waste to commercial landfills. This programme has been extended to the wastewater
treatment plants transferred to Watercare on 1 November 2010. For 2010/11, Watercare diverted from landfills 80% of solid waste generated from the
treatment of wastewater. Over time it is planned to lift performance to 100%.
6E. Percentage performance:
species preservation.
Sustainable environment
PAGE 46
Bird-roost
management
plan
Bird populations
monitored
Adequate bird
roost capacity
Macroinvertebrate
monitoring
Trout
management
plan
Flushing flow
release –
southern dams
Fish trap and
haul –
southern dams
Fish trap and
haul –
western dams
Fish passages
over weirs -–
southern dams
Flushing flow
release –
western dams
2011
100% 7/10
2007 2008 2009 2010
75 80 90 100
% % % %
Watercare carefully manages the discharges from its dams to ensure the downstream ecosystems have sufficient water flow. Compensation and
free-discharge valves have been installed on all the dams which allow the release of a continuous flow of water downstream and to simulate floods and reduce
algae build-up in the streams. To ensure that migration paths of native fish species are not interrupted by the dams, Watercare operates a trap and haul programme for both
fish and eels. Whitebait (juvenile galaxiid species) and elvers (juvenile eels) are trapped in downstream river systems and transferred to upstream of the dam. Adult migrating
eels, generally between 15 and 40 years old, are caught from within the dams and transferred to suitable locations downstream to complete their breeding cycle in the sea.
Weblinks
Greenhouse gas emissions Fig. 37
Initiatives to reduce greenhouse gas emissions Fig. 38
Source of emissions Fig. 39
Watercare’s ecological footprint Fig. 40
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