Intervention record · CHANGE4PLANET

The intervention

TIMELINE

WHAT WAS DEPLOYED

Orange is a city in the Central West of New South Wales that sits at the top of its catchment, which limits the runoff its two supply dams can capture: Spring Creek Dam of 4,450 ML and Suma Park Dam of 18,970 ML [3][6]. Combined storage fell to 26.7% in August 2008 and to 23% in May 2010, with level 5 restrictions in place from May 2008 and a target of 160 litres per person per day [6]. Orange City Council's response was to harvest the runoff from its own streets. Modelling for the July 2008 assessment put the average annual flow past the proposed harvesting site at 11,870 ML per year and found that on average 10 mm of rainfall in the catchment produced about 140 ML of runoff [1]. Stage 1 on Blackmans Swamp Creek was designed as two gross pollutant traps, a rock and gabion weir creating a 3 ML weir pool, a pump station of three variable speed pumps rated at 225 litres per second each with two on duty, a 200 ML holding pond, batch ponds converted from disused sludge ponds, filtration and chlorine dosing, and about 1.7 km of pipeline to a discharge riser on the Suma Park Dam foreshore, a large section of which reused an existing 250 mm pipe that was no longer required [1][6]. The 2008 assessment estimated Stage 1 would yield an average of approximately 1,353 ML per year and cost about $3.5 million [1]; the 2018 case study records that it was built in five months by a council project team with eight major subcontractors for $5 million [6]. Ploughmans Creek followed, four constructed wetlands retrofitted into existing drainage corridors with V-notch weirs and pump stations, assessed in November 2009 as yielding an average of 700 to 800 ML per year at an estimated $4 million [2] and recorded in 2018 as having cost $4.1 million [6]. Licensing conditions imposed during the approvals process reshaped the built design: the on-stream storage component shrank, lowering how much the scheme could capture, and larger pumps were specified to offset that loss [3]. The gap between promise and delivery is the record's central figure. Over the 948 days from 26 November 2017 to 30 June 2020 the scheme extracted 987 ML from a total creek flow of 8,300 ML, 12 per cent, and flow duration curves show extraction confined to high flows with no change in low to moderate flows [3]. The 2021 water balance model, recalibrated on gauge records from June 2009 to June 2020, revised the average annual flow at the harvest weir down from a previous estimate of 9,500 ML per year to 7,055 ML per year, and put average annual extraction for Stage 1 plus the proposed Stage 2 together at 1,113 ML per year, about 16 per cent of that flow [3]. The November 2009 secure yield analysis put the city's baseline secure yield at 4,000 ML per year, rising to 5,000 ML per year with the Blackmans Swamp Creek scheme, 5,500 ML per year with the bores and about 5,900 ML per year with Ploughmans Creek added [2]. In January 2026 the council and the NSW Government stated Stage One contributes approximately 900 ML of secure yield each year, approximately 20 per cent of the water used by Orange, and committed $5 million each to the East Orange Harvesting Wetland for a further 600 ML of secure yield [8][9]. Treated stormwater is analysed for over 240 parameters against targets drawn from the Australian Drinking Water Guidelines and four other guideline documents, and the operator reports that targets are met and that batch pond water is mostly better than the water already in the supply dam, but no fetched source publishes a measured water quality value for the treated harvested stormwater. The only measured water quality data in the fetched sources is the pre-construction raw creek and dam monitoring in the July 2008 assessment [1][2][6][7].

HOW IT WORKS

Physical: two gross pollutant traps, at Dalton Street and Margaret Stevenson Park, remove litter, vegetation and some sediment before harvesting [1][6]. A 2 m high rock and gabion weir on Blackmans Swamp Creek, fitted with an unrestricted 300 mm pipe that passes low flows, creates a 3 ML pool during runoff events which floods an adjacent pump well [3][6]. Pump Station 1 has three variable speed pumps of 225 litres per second, with two duty pumps rotated among the three, for a combined 450 litres per second [6]. Harvested water goes to a 200 ML holding pond, is pumped at about 150 litres per second through a 200 micron filter into in-series batch ponds converted from disused sludge ponds, is dosed with a coagulant, aluminium chlorohydrate, to flocculate and settle solids and attached contaminants, and is then pumped at about 150 litres per second, or 13 ML per day, into Suma Park Dam [1][6]. Water is later drawn from the dam to the Icely Road water treatment plant, where treatment includes ozone and biologically activated carbon filtration [6]. The Ploughmans Creek scheme adds four constructed wetlands, a V-notch weir and pump station on Ploughmans Creek and further pump stations at Somerset Park and Burrendong Way, transferring flows into the same holding pond and batch ponds [2][6]. A separate purple pipe system in Ploughmans Valley and North Orange takes batch pond water through ultraviolet and chlorine treatment for garden watering and toilet flushing in about 4,500 households, in operation since December 2017 [6]. Administrative: harvesting is governed by licence-backed operating rules. The pumps may start only when flow at gauging station GS421051 immediately downstream of the weir exceeds 1,000 litres per second, must stop when the weir pool falls to RL 840.50 m or creek flow falls to 150 litres per second, whichever comes first, must not exceed 450 litres per second combined, must not run when the 200 ML holding pond or Suma Park Dam is at capacity, and must maintain a minimum downstream flow of 2 ML per day in Blackmans Swamp Creek while operating [3]. Water is released from the holding pond as required to top up a downstream landowner's farm dam, and downstream stakeholders must be represented in any review of the operating rules [3]. The scheme is scheduled against the rest of the raw water supply system, including the Macquarie River to Orange pipeline with its 12 ML per day, 108 ML per day, 90 per cent rule and the city's groundwater bores, using a council decision support tool [3]. Water quality is managed under a drinking water management system built to the Australian Drinking Water Guidelines framework, with catchment, system and operational barriers set through HACCP workshops with council staff, the environment agency, the water agency and NSW Health, and including alarms on manholes against sewer overflow, a memorandum of understanding with Fire and Rescue NSW for notification of incidents that generate pollutant runoff, street cleaning in high traffic areas and trade waste controls [1][6][7].

The measurements

9 OUTCOMES

OUTCOMES

METRIC	VALUE	METHOD	MEASURED BY	INDEPENDENT	PERIOD	SRC
Stormwater extracted from Blackmans Swamp Creek since harvesting re-commenced	987 ML over 948 days, being 12% of the 8,300 ML total creek flow over the same period · baseline 8300 (total creek flow at the same gauge over the same 948 days)	Mean daily flow recorded at gauging station GS421051 immediately downstream of the harvesting weir, added to Orange City Council's recorded Pump Station 1 extraction to reconstruct the flow that would have occurred without harvesting; the two series were compared as flow duration curves	Premise Australia for Orange City Council, using data from a gauge installed by Council in 2009 and managed under contract by Water NSW	○	26 November 2017 to 30 June 2020	[3]
Effect of Stage 1 harvesting on the creek flow regime		Flow duration curve comparison of recorded gauge flow against recorded gauge flow plus recorded Pump Station 1 extraction	Premise Australia for Orange City Council	○	26 November 2017 to 30 June 2020	[3]
Additional days of environmental flow release into Summer Hill Creek, attributed jointly to the stormwater harvesting schemes and the Macquarie River to Orange pipeline	128 days (224 days with no environmental flow release with the harvesting schemes operating, against 352 days reconstructed without them) · baseline 352 (reconstructed series without the two transfer schemes)	Recorded combined storage of Suma Park Dam and Spring Creek Reservoir compared with the same series after subtracting the volumes transferred in by stormwater harvesting and the Macquarie River pipeline, tested against the licence condition that suspends environmental flow releases below 25% combined storage and resumes them above 30%	Premise Australia for Orange City Council	○	drought period covered by the assessment, which the report states was completed in October 2020; the start date of the compared series is not stated	[3]
Modelled long-term average annual stormwater extraction from Blackmans Swamp Creek, Stage 1 together with the proposed East Orange Harvesting Wetland	1113 ML/year, about 16% of the modelled 7,055 ML/year average annual flow at the harvest weir; a model result, not a measurement · baseline 7055 (modelled average annual flow at the harvest weir, 1890 to 2020, revised down from a previous estimate of 9,500 ML/year)	Water balance model with components calibrated on gauge GS421051 records from June 2009 to June 2020 and on recorded Pump Station 1 operation, then run on rainfall and evaporation data for January 1890 to December 2020	Premise Australia for Orange City Council	○	1890 to 2020, modelled	[3]
City secure yield with and without the Blackmans Swamp Creek scheme	5000 ML/year with the scheme, against a baseline secure yield of 4,000 ML/year; the bores raise it to 5,500 ML/year and Ploughmans Creek was assessed as adding a further 400 ML/year to about 5,900 ML/year · baseline 4000 (baseline secure yield without the scheme)	Secure yield analysis to the NSW procedure, restrictions not more than 5% of the time, not more often than once in 10 years, and supply of 80% of normal demand through a repeat of the worst drought on record, undertaken for the Integrated Water Cycle Management Strategy	Geolyse for Orange City Council	○	assessment reported November 2009	[2]
Secure yield attributed to Stage 1 at the time of the 2026 funding announcement		Statement in a joint media release by Orange City Council and the NSW Department of Climate Change, Energy, the Environment and Water	Orange City Council and NSW DCCEEW	○	as at January 2026	[8]
Treated harvested stormwater against the scheme's water quality targets		Sampling during harvest events at Blackmans Swamp Creek below the harvesting weir, in Suma Park Dam, in the holding dam and at two depths in each of the two batch ponds, with laboratory analysis; initially batch mode with each batch held until laboratory results confirmed compliance, later continuous mode with in-line turbidity meters and ongoing testing	Orange City Council	○	2009 onward	[6]
Litter, rubbish and organic matter removed from Blackmans Swamp Creek in the first year after installation		not stated in the source	Orange City Council, as reported in the 2018 case study	○	first year following installation	[6]
Downstream aquatic ecology result under the approved Operation Environmental Management Plan		Aquatic Environmental Monitoring Program under the Operation Environmental Management Plan: four sites on Summer Hill Creek downstream of Suma Park Dam, five sites upstream of the Macquarie River pump offtake and four sites downstream, with annual reviews reporting extraction volumes, flows during extraction, water quality and aquatic ecology	Orange City Council under plans approved by the Natural Resources Access Regulator	○	monitoring commenced 2017; statement made in the March 2021 assessment	[3]

● independently measured○ operator-reported· not stated in any source

COST BASIS

CAPITAL: AUD 5,000,000
OPERATING: not published
FUNDING: 6 · 2500000
6
8 · 5000000
8 · 5000000

Scheme by scheme, as stated in sources: Blackmans Swamp Creek Stage 1, $5 million actual [6], against a July 2008 estimate of $3.5 million [1]; Ploughmans Creek, $4.1 million actual [6], against a November 2009 estimate of $4 million [2]; the dual water treatment system, pipes, connections and household audit, $1.5 million [6]; East Orange Harvesting Wetland, $5 million from the NSW Government and $5 million from Orange City Council [8][9]. The 2008 assessment also costed a very different Stage 2, a gated weir creating a 40 ML on-stream harvesting pond, at $1.5 million for a yield rise to approximately 2,190 ML per year [1]; that design was not built and the off-line wetland now proceeding is a different structure at a different price. No cost per megalitre of yield is published and none is calculated here. What the capital figures do not cover is not stated in any source: whether design, approvals, the five year licensing process and the later court proceedings are inside or outside the $5 million and $4.1 million is not disclosed.

The assessment

PRECONDITIONS

A large impervious urban catchment draining past the water supply. Modelling put average annual runoff from the developed Blackmans Swamp Creek catchment at 9,500 ML per year against 2,500 to 3,000 ML per year in its natural state, and urban development in the Ploughmans Creek catchment was assessed as having increased average runoff by 880 ML per year [2][6]
A harvest point close to the storage: Blackmans Swamp Creek runs within 1 km of Suma Park Dam, and an existing 250 mm pipe between the batch ponds and the dam was no longer required and was reused [6]
Existing assets to convert: disused sludge ponds were cleaned out and deepened to become the batch ponds, and road access and power were already at the site [6]
A high level treatment plant already downstream: the Icely Road plant treating Suma Park Dam water uses ozone and biologically activated carbon filtration [6]
Regular harvestable events: the catchment averages 53 rainfall events a year that can be harvested [6]
A regulatory pathway, and in Orange's case a crisis to open it: the scheme started under a 12 month emergency authorisation, extended twice for six months, and only obtained permanent licences after a tribunal decision on 30 March 2015 [3][6]
Downstream entitlements that can be protected and demonstrated to be protected: five licences authorising extraction of 265 ML per year exist downstream of the harvesting pond [1]
Operating rules with hard numeric triggers tied to a gauging station, and instrumentation to prove them: three flow gauging stations were installed to validate flow impacts, and the station immediately below the weir both records flow and controls the pumps [1][3]
A drinking water risk framework applied to a raw water source that no guideline covered: HACCP workshops with state agencies, targets set from the Australian Drinking Water Guidelines, and batch mode operation with every batch held pending laboratory results before continuous operation was allowed [1][6]
Catchment-level control of the contaminant sources, which is only possible because the catchment is the operator's own city: sewer overflow alarms, a memorandum of understanding with Fire and Rescue NSW, trade waste policy, street cleaning and sediment control on building sites [1][6]
One organisation responsible for water supply, sewerage, recycled water and stormwater, which the case study names as a reason design, construction and operation could be done efficiently [6]
Storage in the harvesting system. Urban runoff hydrographs are short; the operator found that the storage lost at approval stage translated straight into lost harvest and heavier pumping, and Stage 2 exists to restore that storage off-line [3]

OPERATOR HINDSIGHT

Stated in the sources themselves. The 2021 assessment [3]: licensing conditions imposed by the state water agency during approvals forced a smaller on-stream storage than the concept design had, which lowered how much the scheme could take, and Pump Station 1 was given more pumping capacity to make up for the storage it lost. The operator's stated lesson is that storage in an urban stormwater harvesting scheme improves harvest capacity because urban runoff hydrographs are short, and that storage also allows smaller extraction pumps; the East Orange Harvesting Wetland exists to restore that storage off-line rather than on-stream. The same document records that the unrestricted 300 mm low flow pipe through the harvesting weir has blocked on some occasions, noting that the minimum flow rule at the gauge still shuts the pumps down. On Ploughmans Creek the design was deliberately changed from a weir to a series of constructed wetlands, which spreads storm flows so harvesting can continue for longer after an event and adds settlement before harvest [7]. The 2018 case study records three reflections from the participants [6]: allow time for engagement with downstream landholders, because submissions against the Blackmans Swamp Creek scheme prolonged the permanent licence approval and schemes that extract from waterways where others hold extraction licences should expect this; supporting guidelines and policies would have helped, because in their absence approval agencies were risk averse and the operator adopted conservative targets and monitoring requirements, which did at least produce a usable data set; and the participants question whether the scheme would have been approved at all without a water shortage crisis.

TRANSFERABILITY ASSESSMENT

AXIS	SCORE	RATIONALE
CAPITAL INTENSITY	●○	Stage 1 cost $5 million and Ploughmans Creek $4.1 million against a city of roughly 40,000 people, with $2.5 million of state emergency drought assistance behind Stage 1 and a $5 million state grant behind Stage 2: a capital program, not routine municipal spending [6][8].
GOVERNANCE DEPENDENCY	○○	Operation began only under a 12 month emergency ministerial authorisation extended twice, permanent licences came only after an inquiry and a tribunal decision on 30 March 2015, and Stage 2 was released only by a Land and Environment Court outcome reported in January 2026 [3][6][8].
ENVIRONMENTAL SPECIFICITY	●○	Needs an urban catchment with reliable runoff, about 53 harvestable events a year, and a harvest point within roughly 1 km of an existing supply storage with an existing pipeline and a high level treatment plant already downstream; broadly applicable in temperate cities, constrained by that geometry [6].
SKILLS AND MAINTENANCE	●○	Run by the council's own water staff, but it requires a drinking water management system built through HACCP workshops, over 240 parameter analysis, gauged pump control, coagulant dosing, a decision support tool and an aquatic monitoring program, and the same consulting firm has been engaged on it since 2007 [3][6].
FUNDING REPEATABILITY	●○	Stage 1 capital came from drought emergency assistance during a declared crisis and Stage 2 from a NSW grant program in 2026, both repeatable state grants rather than routine budget; operation is carried inside the council water function with no published operating cost [6][8].
POLITICAL DURABILITY	●●	The 2021 assessment records that the scheme re-commenced in November 2017 and has operated since, and in January 2026 the council committed $5 million of its own funds to expand it, so the score rests on continuous operation from 2009 to 2026; no fetched source records the intervening changes of council or state administration [3][8].

TOTAL 6/12 · T3

POLITICAL TEST

The scheme was built inside a water crisis and its durability has been tested by regulators and third parties rather than by politics. Combined storage was 26.7% in August 2008 and 23% in May 2010, with level 5 restrictions from May 2008 [6]. Approval came in September 2008 as a 12 month emergency authorisation, extended twice for six months, and harvesting stopped in August 2010 when combined storage reached 50% and the emergency rule closed it down [3][6]. The scheme then sat unused while an inquiry ran into the grant of licences under the Water Act 1912. No fetched source states who initiated that inquiry. Downstream water licence holders were concerned that harvesting would compromise their access to their entitlements, creek care and environmental groups were concerned about creek ecology and changes in flow regimes, submissions against the scheme prolonged the permanent licence approval, and a Land Board hearing was required to obtain the permanent licence; five licences authorising 265 ML per year exist downstream of the harvesting pond [1][6]. A tribunal decision granting licences was handed down on 30 March 2015, more than five years after the process began, and permanent approval for both the Blackmans Swamp Creek and Ploughmans Creek schemes followed in 2015 [3][6]. Harvesting re-commenced on 26 November 2017 and has run since [3]. Stage 2 repeated the pattern: a Review of Environmental Factors in March 2021, council approval under Part 5 in July 2021, then rounds of further information demanded by NRAR, the Department of Planning and Environment and its Biodiversity, Conservation and Science directorate through 2021, 2022 and 2023, including eDNA sampling in October 2023 that detected six taxa and no threatened species, and finally a Land and Environment Court matter reported as resolved in January 2026 [3][4][5][8]. Across that span the council continued to carry the scheme, and in 2026 committed $5 million of its own funds to the East Orange Harvesting Wetland alongside $5 million from the NSW Government [8][9]. No fetched source states that the scheme survived a change of council or of state government, so no such claim is made here. The recurring constraint has never been the disappearance of political support; it has been the length of time a first-of-its-kind approval takes when downstream entitlement holders object.

The file

9 SOURCES

SOURCES

[1] environmental_assessment · Blackmans Swamp Creek Stormwater Harvesting: Review of Environmental Factors · Geolyse Pty Ltd · Prepared for Orange City Council · 2008-07 · en · PRIMARY · www.orange.nsw.gov.au Full 107 page PDF downloaded from the council website and text-extracted. Read the executive summary, the water quality sections 2.3 and 3.6, the Stage 1 and Stage 2 descriptions in section 3.2, the operating rules in section 3.5 and the stakeholder and downstream licence material. Prepared by the council's consulting engineers, so not independent of the operator. The document is a pre-construction assessment: its yield of approximately 1,353 ML per year and its $3.5 million cost are estimates, and its Stage 2 design was not the one built.
[2] environmental_assessment · Ploughmans Creek Stormwater Harvesting Scheme: Review of Environmental Factors, report 208184_REP_001_V2, Final · Geolyse Pty Ltd · Prepared for Orange City Council · 2009-11-23 · en · PRIMARY · www.orange.nsw.gov.au Full 89 page PDF downloaded and text-extracted. Read the executive summary, the harvesting yield section 3.7 with Table 3.7, the quality control section 3.8, the scheme monitoring section 3.9 and the water supply section 8.2 carrying the secure yield analysis. Cover page is dated November 2009 and the issue line is 23 November 2009. Source of the secure yield figures (4,000, 5,000, 5,500 and about 5,900 ML per year), the 700 to 800 ML per year Ploughmans yield, the $4 million estimate, and the single quoted sentence used in confidence_notes.
[3] environmental_assessment · East Orange Harvesting Wetland: Review of Environmental Factors, report 220304_REF_001 Rev B · Premise Australia Pty Ltd (reviewed by Martin Haege, authorised by Andrew Brownlow) · Prepared for Orange City Council · 2021-03-17 · en · PRIMARY · www.orange.nsw.gov.au Full 319 page PDF including appendices downloaded and text-extracted. Read the executive summary and background, section 3.2 on the integrated water supply system, the EOHW structure and the Table 2 operating rules, and section 6.1 in full: environmental flow conditions on Approval 80CA722752, the harvesting operating rules, the existing scheme history and use, monitoring and reporting, the monitored impacts including the 987 ML over 948 days figure, the long term model, the estimated secure yield, likely impacts, the environmental flow release day counts and the increased spill analysis. This is the most load-bearing source in the record and it is the operator's own consultant's work.
[4] environmental_assessment · East Orange Harvesting Wetland: Downstream Impact Assessment, report 220304_REO_003 Rev B · Sally Kirby and Martin Haege, Premise NSW · Prepared for Orange City Council · 2022-10-12 · en · PRIMARY · www.orange.nsw.gov.au Full 44 page PDF downloaded and text-extracted; read the front matter, contents and the introduction and background. Used for the wetland volumes (14 ML permanent water and 36 ML air space as stated here), the Part 5 approval date of July 2021 and the sequence of Biodiversity, Conservation and Science and NRAR correspondence. Its detailed spell and habitat analysis was reviewed but no figure from it is used in this record.
[5] environmental_assessment · East Orange Harvesting Wetland REF: Response to DPE additional data requirements · Premise Australia Pty Ltd · Prepared for Orange City Council · 2023-11-29 · en · PRIMARY · www.orange.nsw.gov.au Full 47 page PDF downloaded and text-extracted; read the introduction, the fish and eDNA sections and the hydrology and spell analysis section. Used only for the October 2023 eDNA sampling (three sites, three replicates each, six taxa detected, no threatened species) and as evidence of the length and content of the Stage 2 approval process.
[6] case_study · Orange Stormwater to Potable: Building urban water supply diversity · Cooperative Research Centre for Water Sensitive Cities, Monash University · 2018-05 · en · INDEPENDENT · watersensitivecities.org.au Full 40 page PDF downloaded and text-extracted and read end to end: context, drivers, innovations including the two technology focus pages on Blackmans Swamp Creek and Ploughmans Creek, water quality management, weir design, the dual water scheme, outcomes, challenges and lessons. Published by an Australian research centre, so independent of the operator, but the content is drawn from interviews with Orange City Council staff and the designing consultant Geolyse and the photographs are credited to them, so its figures are operator-sourced. It is the only fetched source stating the actual construction costs ($5 million, $4.1 million, $1.5 million), the $2.5 million emergency funding, the 240 parameter monitoring program and the 182 tonne gross pollutant figure.
[7] operator_web_page · Stormwater (Water), Orange City Council · Orange City Council · accessed 2026-08-16 · en · PRIMARY · www.orange.nsw.gov.au Page read in a browser because the site returns HTTP 403 to automated fetch tools. Gives the August 2009 opening date, the emergency funding origin, the 2010 construction of the Ploughmans Creek wetlands and the reason the design was changed to wetlands, the Australian Drinking Water Guidelines framework risk assessment and drinking water management system, and the current approvals status of the East Orange Harvesting Wetland. It is also the index page from which every assessment document above was downloaded. Undated, so published_on is null. Not re-verifiable by automated fetch at review time: the page returned HTTP 403 again on 2026-08-16. One claim in this record rests on this source alone, the statement in what operators would change that the Ploughmans Creek design was changed from a weir to a series of constructed wetlands to spread storm flows and add settlement before harvest.
[8] media_release · Boost For Orange Stormwater Harvesting · Orange City Council with the NSW Department of Climate Change, Energy, the Environment and Water, republished by Mirage News · 2026-01-07 · en · PRIMARY · www.miragenews.com Full release fetched and read through the Mirage News verbatim republication, because orange.nsw.gov.au returns HTTP 403 to automated fetch tools. Carries the $5 million plus $5 million funding, the approximately 900 ML secure yield and approximately 20 per cent of city water for Stage One, the additional 600 ML for the East Orange Harvesting Wetland, the 13 ML wetland pond, the resolution of the Land and Environment Court matter, the construction window of late 2026 to 2027, the 42,000 resident figure, and quoted statements from the NSW grant programs director and the mayor. It is the operator's and the funder's own statement, so primary but not independent.
[9] news_feature · Orange expands stormwater harvesting to boost drought resilience · Chris Edwards · Inside Water · 2026-01-14 · en · INDEPENDENT · insidewater.com.au Full article fetched and read. Independent trade coverage of the January 2026 announcement, repeating the same figures as the media release without adding measurement. Used only to corroborate the funding split, the 900 ML and 600 ML secure yield figures and the construction timing.

RECORD

PUBLISHED: 2026-08-16
LAST VERIFIED: 2026-08-16
REVIEW DUE: 2027-02-16
RUBRIC: v1.0
STATUS HISTORY: 2026-08-16 · operating · Record published.
RIGHT OF REPLY: Not required under rubric v1.0 for an operating record. Because this record sets the scheme's measured extraction and its later modelled yield against the pre-construction estimates, and because it documents a contested licensing history and the absence of published water quality data, right of reply will be offered to Orange City Council before this record is promoted or distributed, and any response received will be published here in full.
LANGUAGE: All sources are English-language publications of an Australian local council, its consulting engineers, an Australian cooperative research centre, an Australian state government funder and an Australian trade publication. All money is Australian dollars. ML means megalitre, one million litres, as defined in the glossaries of the two Geolyse assessments [1][2]. RL 840.50 m and RL 840.5 AHD refer to reduced level above the Australian Height Datum. The January 2026 media release was read through a verbatim republication by Mirage News because the council website refuses automated fetches.
CONFIDENCE: Solid: every figure in this record was read directly from a document that was downloaded and text-extracted or from a page read in full, not from an abstract or a search summary. The measured extraction total of 987 ML from 8,300 ML of creek flow over 948 days, the operating rules with their numeric triggers, the licence history including the 30 March 2015 tribunal decision and the 26 November 2017 re-commencement, the recalibrated 7,055 ML per year average flow and the 1,113 ML per year modelled extraction, and the 128 day environmental flow result all come from the March 2021 assessment [3]. The secure yield series (4,000, 5,000, 5,500, about 5,900 ML per year) and the Ploughmans yield and cost estimate come from the November 2009 assessment [2]. The construction costs come from the 2018 case study [6] and the 2026 funding and secure yield statements from the joint media release [8]. Thin or judgment-based, and where sources disagree: (a) Yield figures are not comparable with each other and must not be read as a series. The 2008 pre-construction estimate of approximately 1,353 ML per year for Stage 1 alone [1], the 2018 case study's average harvesting potential of 1,350 ML per year for both schemes combined, 850 from Blackmans Swamp Creek and up to 500 from Ploughmans Creek [6], the 2021 model's 1,113 ML per year long-term average extraction for Stage 1 plus the unbuilt Stage 2 [3], and the 2026 claim of approximately 900 ML per year of secure yield for Stage One [8] are four different quantities measured four different ways. Secure yield is a drought-security concept defined by the NSW 5, 10 and 20 per cent rules [2] and is not the same as average annual extraction. No year-by-year record of megalitres actually harvested is published in any fetched source. (b) The average annual flow at the harvest weir has been restated three times: 11,870 ML per year in 2008 [1], a previous estimate of 9,500 ML per year, and 7,055 ML per year after recalibration on eleven years of gauge data [3]. The 2018 case study separately gives 9,500 ML per year for average annual runoff from the developed catchment against 2,500 to 3,000 ML per year in its natural state [6]. (c) No measured water quality value for the treated harvested stormwater is published anywhere in the fetched sources. The July 2008 assessment does publish measured pre-construction raw water quality for Blackmans Swamp Creek and Suma Park Dam, including a suspended solids average of about 70 mg/L at the STP Crossing with a maximum of 455 mg/L, turbidity from 3 to 333 NTU, and faecal coliforms averaging 20,000 cfu/100mL and ranging from 3,000 to 53,000 cfu/100mL [1]. The operator states that over 240 parameters are analysed against targets and that batch pond water is mostly better than the water already in Suma Park Dam [6], and the November 2009 assessment states of the existing scheme that "To date, all scheme targets have been met." [2] On this outcome alone the evidence would grade E4, and the record's E3 attaches to the volume and hydrology outcomes, not to water quality. (d) Physical figures disagree between sources: the holding pond is 200 ML in the 2008 and 2021 assessments [1][3] and 230 ML in the 2018 case study [6]; the batch pond is 50 ML with 50 ML batches in 2008 [1] and the batches are 34 ML in the 2018 case study [6]; the East Orange wetland is 13 ML permanent water with 30 ML of airspace in the 2021 assessment's structural section and 14 ML with 36 ML in its own background section and in the 2022 assessment [3][4], and 13 ML in the 2026 release [8]. None of these were reconciled. (e) No operating cost is published for any of the schemes, so operating_annual is null, and no cost per megalitre is published or calculated here. What the $5 million and $4.1 million capital figures include is not stated. (f) capital_year is null because no source states a dollar year. (g) population_served is null because no source states a service population; the two population figures available are approximate and describe the local government area or the town, not the supply. (h) The claim that this was the first large scale indirect to potable stormwater harvesting project in Australia is made by the operator, the state funder, the research centre case study and the trade press [6][7][8][9]; no source independently verifies it. (i) The Land and Environment Court decision that released Stage 2 is reported only as resolved; no fetched source gives its date, citation or reasons, and the decision itself was not obtained. (j) The Köppen classification Cfb is a general climate classification and is not taken from any fetched source. (k) The downstream aquatic monitoring program has been running since 2017 and its operator states that no conclusion about ecological effect is yet possible because drought obscured detection [3], so the record makes no claim about downstream ecological outcome in either direction. (l) The 128 additional days of environmental flow release are attributed by the source jointly to stormwater harvesting and the Macquarie River to Orange pipeline and cannot be attributed to stormwater harvesting alone [3]. No measured, costed or modelled figure in this record was estimated, interpolated or arithmetically derived by the registry, and every null reflects an absence in the sources. Three counts are the registry's own arithmetic over dates and site counts that the sources state, and are not source figures: the elapsed spans given in the political test and the political test summary, and the decimal conversion of the city centroid coordinates in the location notes, whose degrees and minutes are not taken from any fetched source.

CITE THIS RECORD

change4planet.org. C4P-WTR-0003: Urban stormwater harvested into a drinking water dam (Blackmans Swamp Creek and Ploughmans Creek), Orange, New South Wales: council-scale operation since 2009 under contested licences. Grades T3/E3 (rubric v1.0). Last verified 2026-08-16. https://change4planet.org/records/c4p-wtr-0003-orange-stormwater-harvesting-australia