Integrated Water Operations

Designed vs Delivered — Scheme performance against IWM Plan targets

Last rolled up 09:42 · Source: sensor traces · Audit trail available

97%

Catchment L Harvesting

of design intent

126 / 130 ML/yr reuse

85%

Catchment A

of design intent

12.8 / 15 ML/yr

92%

Catchment C WSUD

of design intent

TN removal 41% vs 45% target

78%

Catchment D Wetland

of design intent

overflow 145 kL vs 200 kL limit

Total Sites

47

Across 12 catchments

Active Alerts

3

3 open · 18 this month · 64 YTD

Predicted Events

5

Next 6 hours

Network Uptime

99.7%

+0.2% vs last month

Data Quality

96.3%

+1.1% this week

Showing 75 of 75 assets

0

Catchments

Catchment A

PS-001, WL-003

◆ IWM Plan 2018

4 1

Catchment D East

TK-010, PS-007

3 1

Catchment C

CSO-004, DET-002

◆ IWM Plan 2018

4 2

Catchment M

FM-012, PS-003

3

Catchment B

UV-002

◆ IWM Plan 2018

4

Catchment E

PS-012

3

Catchment F

PS-015, FM-020

3

Catchment G

PS-018, TK-015

5 1

Catchment H

PS-020, WL-008

4

Catchment I

PS-022, FM-025

3

Catchment J

PS-025, CSO-008

4 1

Catchment K

PS-028, FM-030

3

Network Health

94.2%

IWM Plan compliance: 96.3%

Rainfall Forecast — Catchment A

Live

Recent Activity

DET-002 Overflow Risk
Basin level 87%, rain forecast 15mm/hr · 4 min ago

›

PS-007 Pump Cycling
Abnormal start/stop frequency · 12 min ago

›

Monthly EPA submission
Jan 2026 Catchment D pack generated · 01 Feb 2026 · Auto

›

Site inspection
Catchment A bioretention, quarterly · Reviewed by MY · 21 Mar 2026

›

Catchment C scheme rev 3 uploaded
As-built vs design reconciliation complete · AD · 14 Mar 2026

›

UV-002 lamp replacement
Scheduled preventive maintenance · WO-4291 · 14 Feb 2026

›

E. Manager sign-off
Catchment D Q4 Scheme Performance Report · 15 Feb 2026

›

CSO-004 post-event review
Catchment C 03 Dec event, capacity uplift recommended · 18 Dec 2025

›

Pipe Network — Capacity Utilisation i

LiveInferred Flow

Flow derived from 47 level sensors (wet wells, detention basins, junction pits) using continuous inference. Replaces conventional pipe-flow metering — no flow meters required on the trunk network. Validated against 4 gauged reference sites (BoM + Melbourne Water).

Model Validation — Inferred vs Gauged Flow Continuous Calibration

Nash-Sutcliffe Efficiency

0.87

Validated against 4 gauged reference sites over 18 months

RMSE (peak flow)

0.14 m³/s

Across 12 monitored catchments

Last calibration

03 Feb 2026

Auto-recalibrates weekly from incoming sensor data

Reference sites

BoM ■■■■■■■

MW  ■■■■■■■■

MW  ■■■■■■■

■■■■■■ ■■■■■

4 gauged flow stations · identifiers on engagement

Inferred Flow vs Gauged — DN450 Trunk Main South (Validation Site)

Level-Derived Flow

R²

0.94

RMSE

1.8 L/s

Peak

35 L/s @ 15:00

Pipe util

80%

Detention Basin Fill Curve — With vs Without Diversion

Time to overflow

2h 47m

Act within

45 min

Peak predicted

98% @ 3h

With diversion

88% peak

Dynamic Threshold — Level Sensor PS-001

Adaptive AI

The threshold adapts to diurnal flow patterns (normal daily usage cycles) and forecast rainfall, so it rises before a storm arrives. Static SCADA thresholds can't distinguish a rain event from a blockage.

Static SCADA threshold (traditional) IWO dynamic threshold (adapts to conditions) Actual level

97%

Alarm reduction

842 → 26

Monthly alarms

100%

Real events caught

0

Missed critical events

Same network. Same sensors. Different intelligence.

Model v2.4.1 · Training set: 18 months · Last retrain 09 Apr 2026 · Validated against 4 gauged reference sites · Model card ↗

Select an alert to view details

Catchment A

Operational

2.4 ML captured75% reuse47% storage

Design: IWM Plan 2018 rev 3 · Commissioned Aug 2019

Catchment D Wetland

Warning

1.8 ML captured68% reuse82% storage

Design: WSUD Strategy 2017 · Commissioned Nov 2018

Catchment C WSUD

Operational

3.1 ML captured81% reuse35% storage

Design: IWM Plan 2019 · Commissioned Apr 2020

Catchment B Reuse

Operational

0.9 ML captured72% reuse58% storage

Design: Water authority + design partner joint study 2016 · Commissioned Mar 2017

Catchment L Harvesting

Operational

126 ML/yr reuse97% of design7,000 m² treatment

Design: Design lead 2012-2015 · Commissioned Aug 2015 · $100M scheme

Potable Water Saved (YTD)

2,840 kL

Mains water offset: 34%

Water Captured (MTD)

2.4 ML

↑ 18% vs last month

Water Reused (MTD)

1.8 ML

75% reuse rate

Treatment Compliance

100%

All parameters within limits

Storage Available

420 kL

of 800 kL capacity

Mains water offset (YTD)

2.84 ML

Potable offset · equivalent to 23 households/day

72-Hour Rainfall Forecast & Capture Prediction

AI Forecast

72h forecast | Expected capture: 45 kL | Storage impact: 47% → 78% | Next rain: Thu 08:00 hover bars for per-hour detail

Stormwater Harvesting Scheme — Catchment A

Live

Catchment

45 ha
Runoff: 12 L/s

C=0.35 · 100yr ARI: 820 L/s

4 assets

Gross Pollutant Trap

Flow: 12 L/s
Clean

Humegard HG2400 · 85 L/s capacity · last service 14 Feb

4 assets

Bioretention / Wetland

Turbidity: 8.2 NTU
pH: 7.1

1,200 m² · filter media 0.8m · FAWB 2009 spec

6 assets

Storage Tank

Level: 47.5%
380 / 800 kL

Atlantis modular HDPE · 800 kL · installed 2018

8 assets

UV / Filtration

UV Dose: 42 mJ/cm²
Online

Trojan UVSwift SC3 · lamp hrs 8,204 / 9,000 · replace due Feb

6 assets

Reuse

Irrigation: 4.2 L/s
Toilet: 1.8 L/s

End uses: irrigation · toilet · washdown · 34% potable offset

6 assets

Storage Level — Predicted Fill/Draw-down

Reuse Demand vs Available Treated Water

Water Balance — This Month

EPA Compliance — Water Quality

Parameter	Result	Limit	Status
Turbidity	3.2 NTU	< 5 NTU	Pass
E. coli	<1 CFU/100mL	<10 CFU/100mL	Pass
pH	7.1	6.5 — 8.5	Pass
TSS	8 mg/L	< 30 mg/L	Pass
Total N	4.2 mg/L	< 10 mg/L	Pass
Total P	0.9 mg/L	< 1.0 mg/L	Near Limit

⚠ Total P trending upward — recommend bioretention maintenance review

BPEM Removal Performance — YTD vs EPA Targets

TSS84% / 80%

TP48% / 45%

TN41% / 45%

Litter78% / 70%

TN removal trending below target — bioretention filter media nearing end of service life (6 yrs). Rectification under review by A. Reviewer.

Design vs Actual Performance

Metric	Design (2018 IWM Plan)	Year 1 (2019–20)	Year 2 (2020–21)	Current (2025–26)	Variance
Annual yield (ML)	15.0	9.8	11.6	12.8	–2.2 ML · within range for asset age
Reuse rate	80%	62%	70%	75%	–5pp · demand ramp-up ongoing
Overflow volume (kL/yr)	<200	310	220	145	within EPA limit
Potable offset (ML/yr)	12.0	6.1	8.1	9.6	–2.4 ML · tracking to 80% by 2027

Year-over-year: Scheme has trended toward design yield as vegetation matured and reuse demand ramped. Current year 85% of design — within expected maturation curve documented in 2018 IWM Plan Appendix C. Next review: annual performance report due 30 Jun 2026 (auto-generated).

Overflow Events (YTD) Within EPA annual limit (< 200 kL)

3 events • Total volume: 145 kL

Date	Duration	Volume	Receiving Water
14 Jan 2026	2.5 hrs	45 kL	Skeleton Creek
28 Dec 2025	1.2 hrs	18 kL	Skeleton Creek
15 Nov 2025	4.1 hrs	82 kL	Skeleton Creek

Auto-logged from sensor traces · Each event cross-referenced against BoM rain gauge + Melbourne Water flow archive Last reviewed: E. Manager · 15 Feb 2026

Excess I&I Flow

34 L/s

Across 5 affected catchments

Annual Cost Impact

$286K

Excess treatment @ $8.40/kL

4.2% of total network treatment cost

Segments Flagged

12

Of 148 monitored

Addressable Savings

$186K/yr

Top 4 segments remediated

Estimated payback: 5.8 months on top 4 segments

Detection methodology Minimum night flow (MNF) analysis · Dry weather baseline Nov 2024 – Jan 2025 · 3σ threshold against baseline per segment · Groundwater-driven I&I isolated via wet/dry weather flow decomposition · References: WSAA Sewer Code of Practice WSA 02–2014, Melbourne Water Sewer Standards

Last baseline refresh
03 Mar 2026

I&I Severity — Pipe NetworkAnomaly Detection

Fix Priority — Ranked by ROI

Dry Weather vs Wet Weather Flow — Catchment C DN375

I&I Trend — Catchment C DN375

Seasonality — I&I Flow 18-Month Trend i Winter 2025 vs Winter 2024: –14% after manhole sealing programme

Nov '24 Apr '25 peak Summer min Remediation starts Apr '26

Peak winter I&I

52 L/s

Apr 2025

Baseline (dry)

18 L/s

Aug 2025

Post-remediation

34 L/s

Current · 4 segments sealed

Remediation Results4 completed

Segment	Fix Type	Completed	Flow Before	Flow After	Reduction	Annual Savings
SEG-T04 Catchment A West	Manhole Seal	Nov 2025	4.0 L/s	0.8 L/s	↓ 80%	$27K/yr
SEG-R03 Westcott Pde	Manhole Seal	Dec 2025	3.8 L/s	0.9 L/s	↓ 76%	$24K/yr
SEG-R04 Station Rd	Manhole Seal	Jan 2026	5.4 L/s	1.2 L/s	↓ 78%	$35K/yr
SEG-M02 Coburns Rd	Manhole Seal	Feb 2026	3.1 L/s	0.7 L/s	↓ 77%	$20K/yr

Draft cycle time

4.2 min

Mean • engineering review required prior to issue

Data completeness

96.4%

Across sensors, lab samples & operator logs

Pending review

2

In engineering review queue

Open exceptions

6

In action register • 2 priority Med, 4 Low

Report for: Period:

Integrated Water
Operations

by StreamwiseAI

Draft for Engineering Review

IWM Scheme Performance & Operational Assurance Report

Catchment D East Stormwater Harvesting Scheme — January 2026

Reporting Period: January 2026 • Generated: 01 Feb 2026

Classification: Confidential • Prepared for: the water authority

Ref: RPT-PCE-2026-01-001

Prepared by: Integrated Water Designer • Reviewed by: A. Reviewer • Signed off: E. Manager

Document hash: sha256:a3f2…c841 • Version 1.0 • View audit trail ↗

Draft for Engineering Review Generated 01 Feb 2026 · Revision A · Engineering review required prior to issue

1. Document Control

Document number	SPR-PCE-2026-01-A	Revision	A (Draft)
Asset / scheme	Catchment D East Stormwater Harvesting Scheme	Reporting period	01 Jan – 31 Jan 2026
Status	Draft for Engineering Review	Issue date	01 Feb 2026 (auto-compiled)
Prepared by	Integrated Water Operations platform · auto-compiled	Compiled at	01 Feb 2026 · 00:04 AEDT
Reviewed by	A. Reviewer — Principal Engineer · CPEng 5142109 · NER 1018442	Review status	Pending — review window 02–04 Feb
Approved by	E. Manager — Engineering Manager (post engineering review)	Approval status	Pending engineering review
Distribution	Water Authority Operations · Asset Owner · Catchment Management Authority · Designer file (informational)
Data sources	Continuous telemetry (47 tags · 5-min cadence) · Eurofins ARL laboratory analyses (NATA 1261) · BoM rainfall GAUGE-012 + GAUGE-009 · Operator event logs · Asset register · MUSIC v6.3 design model

Limitations This report has been prepared using available telemetry, laboratory results and operational records for the nominated reporting period. Results should be interpreted in the context of sensor calibration status, rainfall conditions, maintenance history and adopted design assumptions documented in the Detailed Design Report (DDR-PCE-A, Sep 2024). Pollutant retention values are derived from inferred catchment runoff and measured outflow concentrations — the inflow figure is a model estimate and carries the uncertainties of the source rainfall product. Where laboratory results are pending or sensor records are incomplete, the affected metric is annotated.

2. Executive Summary

The Catchment D East stormwater harvesting scheme operated within adopted performance and compliance limits for the January 2026 reporting period. The system captured an estimated 2.4 ML of stormwater (against design assumption of 2.1 ML) and supplied 1.8 ML for reuse, representing a 75% reuse efficiency.

No reportable discharge exceedances or environmental incidents were recorded. Three operational exceptions are noted in this report: (i) a short-duration Total Phosphorus trend approaching the adopted trigger level following the 14 Jan rainfall event, (ii) a 42-min comms dropout on level sensor LS-D14 (data inferred from adjacent nodes during the dropout window), and (iii) UV lamp bank operating hours approaching the recommended replacement threshold. Each is logged in the action register (Section 9).

The scheme generally performed in line with design intent. Treatment performance exceeded adopted BPEM targets for TSS, Total Phosphorus and Total Nitrogen. Recommended actions for February include UV lamp replacement planning, GPT basket inspection and continued monitoring of phosphorus trends during wet weather events.

3. Reporting Period Conditions

Total rainfall

61 mm

+13% on 12-yr LT avg (54 mm)

Discrete events

8

≥1 mm rainfall events

Largest event

18 mm / 90 min

14 Jan 2026 · ARI ~1-in-2

Antecedent dry period

11 days

prior to first event of period

Parameter	This period	YTD	12-yr LT avg	Comment
Inferred catchment runoff (ML)	3.2 ML	3.2 ML	2.8 ML	Wetter than average; runoff coefficient ~0.42
Volume captured to scheme (ML)	2.4 ML	2.4 ML	2.1 ML	Above design (+14%) — within capture infrastructure capacity
Reuse demand satisfied (ML)	1.8 ML	1.8 ML	1.6 ML	Slightly below design (1.9 ML) due to mild summer demand
Reuse efficiency	75%	75%	76%	Within design envelope (75–82% expected range)
Spill / overflow events	0	0	0.4 / mo	No bypass; tank peak utilisation 88% on 14 Jan
Operational constraints	Routine sensor recalibration completed 18 Jan (4-hr scheduled outage of WQ panel — covered by grab samples). UV-D05 lamp service flagged for Feb based on operating hours. No unplanned outages recorded.			—

4. Design Intent vs Actual Performance

Design assumptions sourced from MUSIC v6.3 (DDR-PCE-A, Sep 2024). Measured values from continuous sensors + Eurofins ARL grab sample composites. Variance positive where actual outperforms design.

Metric	Design assumption	Measured / inferred	Variance	Comment
Capture volume	2.1 ML / month	2.4 ML / month	+14%	Above design; driven by wetter-than-average rainfall (+13%)
Reuse demand satisfied	1.9 ML / month	1.8 ML / month	−5%	Slightly below design — mild summer + 1 customer pause
TSS reduction (BPEM)	≥80%	84%	+4 pp	Exceeds BPEM target; consistent with prior 6 months
Total Phosphorus reduction (BPEM)	≥45%	48%	+3 pp	Within expected range; trending lightly upward — see §5
Total Nitrogen reduction (BPEM)	≥45%	46%	+1 pp	Marginal exceedance of target — within design uncertainty
Overflow / bypass events	≤1 / month	0	better	No bypass recorded; peak tank utilisation 88% on 14 Jan
Treatment availability	≥97%	98.6%	+1.6 pp	Exceeds design availability target
Energy intensity (kWh / ML treated)	≤95	88	−7%	Better than design — VSD optimisation effective

5. Water Quality Results

Median and 95th percentile reported per AS/NZS 5667.1 statistical practice. Source code: S = continuous sensor (5-min cadence) · L = laboratory composite (Eurofins ARL, NATA 1261) · I = inferred from cross-correlated tags. Adopted triggers per the scheme operating envelope (DDR-PCE-A §7) and SEPP Waters of Vic Schedule F8 where applicable.

Parameter	Unit	Source	Median	95th %ile	Maximum	Adopted trigger	Status	Comment
Turbidity	NTU	S + L	2.6	4.4	4.8	5.0	Watch	95th %ile within trigger but elevated relative to LT median (2.1)
E. coli	CFU/100mL	L	<1	2	3	10	Within trigger	31 weekly samples; one rescheduled 22 Jan (lab logistics)
pH	—	S	7.2	7.7	7.8	6.5–8.5	Within trigger	Stable; no diurnal trend outside expected range
TSS	mg/L	S + L	5.8	11	12	30	Within trigger	Brief 18 mg/L spike during 14 Jan event; auto-resolved 5 min
Total Nitrogen	mg/L	L	3.0	4.6	4.8	10	Within trigger	Within design envelope; no trend
Total Phosphorus	mg/L	L	0.84	0.96	1.0	1.0 (action 0.85)	Watch	Approaching adopted action trigger after 14 Jan event — see §7 OE-2026-01
Dissolved Oxygen	mg/L	S	7.4	6.4	6.2 (min)	≥4.0	Within trigger	Robust; minimum well above trigger
Conductivity	µS/cm	S	475	590	620	1500	Within trigger	Stable
Chemical oxygen demand	mg/L	L	—	—	—	40	Not reportable	Not in monthly programme; quarterly schedule next due Mar 2026

6. Treatment Train Asset Performance

Asset	Function	Current status	Evidence	Action
GPT-D01	Gross pollutant removal (CDS-style)	Service due	Basket fill 62% (visual + load cell trend)	Inspect within 2 weeks · A-026
SED-D02	Sediment forebay	Performing	Sediment depth 0.18 m (design ≤0.30 m)	Routine quarterly inspection
BIO-D03	Bioretention basin (filter media 600 mm)	Performing	Infiltration 185 mm/hr (design 100–300)	Continue routine monitoring
WET-D04	Constructed wetland (3 cells)	Performing	Macrophyte cover 92% (design ≥80%)	No action this period
UV-D05	UV disinfection (post-storage)	Watch	Lamp output 78% · operating hrs 8,200 / 9,000 rated	Plan replacement Feb · A-028
TANK-D06	Below-ground storage (4.5 ML)	Performing	Mean utilisation 62% (peak 88% on 14 Jan)	None
PUMP-D06	Reuse delivery pump	Performing	Availability 98.4% (target ≥97%)	None
LS-D14	Storage tank level sensor	Comms event	42-min dropout 21 Jan; restored unaided	Confirm comms stability · A-029

7. Operational Exceptions

Operational exceptions are events that warrant operator attention or action but did not constitute a regulatory non-conformance. Material exceptions are also reflected in the action register (§9).

ID	Date / time (AEDT)	Exception	Duration	Impact	Response	Status
OE-2026-01	14 Jan 2026 · 16:20	Total Phosphorus trend approaching adopted action trigger (0.85 mg/L) following rainfall event	~3.5 hr	No discharge exceedance · trigger not breached	Trend monitored via continuous WQ panel; lab composite confirmed return to median by 22 Jan	Closed
OE-2026-02	21 Jan 2026 · 09:10	Level sensor LS-D14 comms dropout	42 min	Tank level inferred from adjacent nodes · cross-check <1% deviation	Comms restored unaided · follow-up scheduled to confirm stability (A-029)	Closed
OE-2026-03	27 Jan 2026 · 11:35	UV-D05 lamp operating-hours warning (8,200 hr of 9,000 rated)	Ongoing	Disinfection performance unaffected · preventive replacement required	Work order WO-4291 raised; lamp pre-ordered (A-028)	Open

8. Data Quality and Assumptions

Data source	Completeness	Confidence	Notes
Level sensors (12 tags)	98.6%	High	Two short comms dropouts (LS-D14 21 Jan · LS-D08 09 Jan); data inferred from adjacent nodes
Rainfall (BoM GAUGE-012 + local tipping bucket)	100%	High	BoM official record + local cross-validation; both within ±3%
Continuous water-quality sensors (8 tags)	96.4%	Medium	Routine NATA-traceable calibration completed 18 Jan; 4-hr planned outage covered by grab samples
Laboratory composite samples (Eurofins ARL)	96.8%	Medium	30 of 31 samples returned; one rescheduled (22 Jan) due to lab logistics — re-collected 23 Jan
Operator event logs & field reports	100%	Medium	Manually reviewed by Operations Engineer prior to issue; free-text fields cross-checked against work-order register
MUSIC v6.3 design model (re-run)	100%	High	Original design model re-run with January 2026 rainfall record; pollutant retention compared
Asset register & maintenance history	100%	High	Live asset register · last reconciliation 02 Jan 2026

Adopted assumptions: Inflow load is calculated using BoM rainfall × calibrated runoff coefficient (0.42, derived from prior-year flow gauging). Outflow load uses lab composite concentrations × measured outflow volume. BPEM target performance is annualised; this monthly figure represents performance under January conditions only. MUSIC re-run uses the same EMC values as the original design; if the next quarterly review indicates persistent deviation, EMC re-calibration will be recommended (action A-027).

8.1 Automated Validation Log

Corrections applied during compilation, before engineering review. Each entry is annotated at the affected record; source documents are never altered.

Date	Check	Finding	Resolution
01 Feb	Unit consistency (lab import)	Eurofins COA-2026-01-D02 TP result received in µg/L against a mg/L register field	Converted at import and annotated; COA source unchanged
01 Feb	Duplicate detection	COA-2026-01-D03 received twice from the lab portal	Deduplicated; single record retained with both receipt timestamps logged
21 Jan	Telemetry continuity	LS-D14 comms dropout, 12 min	Inferred from adjacent nodes, flagged in §8; follow-up raised as A-029
15 Jan	Field / telemetry cross-check	Field report recorded GPT-D01 basket fill as 26%; load-cell trend read 62%	Transposition confirmed with operator; register corrected, inspection raised as A-026
09 Jan	Telemetry continuity	LS-D08 comms dropout, 8 min	Inferred from adjacent nodes, flagged in §8

This period: 2.4M readings validated · 214 cross-checks run · 5 corrections applied before review · 0 corrections required after issue (12-month record).

9. Action Register

Open and recently closed actions. Carried forward from prior periods or raised this period. Owners assigned in the asset management system.

ID	Action	Priority	Owner	Due	Status
A-026	Inspect GPT-D01 basket and remove accumulated gross pollutants (62% fill)	Medium	Maintenance	09 Feb 2026	Scheduled
A-027	Review TP trend during next wet-weather event; consider EMC re-calibration if pattern persists	Low	Water Quality	28 Feb 2026	Monitoring
A-028	Plan UV-D05 lamp replacement (parts pre-ordered; install during scheduled February maintenance window)	Medium	Operations	16 Feb 2026	Open
A-029	Confirm LS-D14 comms stability after 21 Jan dropout — verify modem RSSI and antenna alignment	Low	SCADA / Telemetry	07 Feb 2026	Open
A-024	Macrophyte density review — Cell 2 trending up · prior period	Low	Operations	15 Mar 2026	Carried fwd
A-025	Quarterly NATA calibration scheduled (next 18 Apr 2026) · prior period	Low	SCADA / Telemetry	18 Apr 2026	Carried fwd

10. Review and Sign-off

Document lifecycle. Draft generated automatically from validated telemetry, laboratory results and operator logs. Engineering review is required prior to external issue or regulatory submission. Reviewer to confirm exception interpretation, action register completeness, and laboratory result narrative. Approver to confirm endorsement for distribution. Final issued copy is hash-stamped and archived.

Compiled (auto)

Integrated Water Operations

Platform · auto-compiled from validated data

01 Feb 2026 · 00:04 AEDT

Engineering Review

A. Reviewer

Principal Engineer · CPEng 5142109 · NER 1018442

Pending — review window 02–04 Feb 2026

Approval & Issue

E. Manager

Engineering Manager · CPEng 5106827

Pending engineering review

Appendices

AContinuous sensor traces (47 tags · 5-min cadence) — Parquet + CSV bundleaudit-hash verified

BEurofins ARL Certificates of Analysis — COA-2026-01-D01 to COA-2026-01-D04NATA 1261

CCalibration records — turbidity, pH, DO, conductivity (last cal. 18 Jan 2026)NATA chain

DBoM rainfall extract — GAUGE-012 / GAUGE-009 (1-min interval, full month)BoM

EMUSIC v6.3 model re-run — Jan 2026 conditions vs designeWater

FOperator event log (full month) & work-order register extractinternal

GAsset inspection photos & field notes (W4280 / W4287 / W4291)internal

HAudit trail — every read of every record (tamper-evident JSONL)platform

Report Templates

IWM Scheme Performance Report

Operational assurance • design intent vs actual • exceptions

Draft

Network Operations Exception Report

Internal ops • priority exceptions • work orders • alarm review

Internal

Event Investigation Report

Single-event • evidence • modelled cause • lessons learned

On-demand

Monthly Compliance Summary

Regulator-facing • licence obligations • sampling completion

Approved

Annual Scheme Performance Review

Year 1 retrospective • MUSIC re-calibration • design vs actual

Designer

Council Quarterly Performance Summary

Service Agreement KPIs • community outcomes • capital works

Auto

Evidence Pack / Audit Trail

Hash-verified bundle • chain of custody • expert-witness ready

Evidence

Evidence Pack export Expert witness ready

Bundle raw sensor traces, calibration records, event timeline, BoM rain gauge extract, photo log references, and expert-witness statement template. Signed, versioned, hash-verified.

Sensor traces CSV47 tags • 18 months

Calibration logNATA chain

BoM rain archiveGAUGE-012

Audit trailHash-verified

Compliance Trend

Engineering Hours ReturnedQ1 to date · 39.8 hrs

EPA Monthly pack · Jan, Catchment D

Compiled 4.2 min • manual baseline 6.0 hrs

5.9 hrs

CSO-004 post-event evidence pack

Rain + level + flow + diversion auto-correlated • baseline ~10 hrs

9.6 hrs

Q4 sign-off routing · Catchment D

18/18 KPIs pre-populated • cycle 9 days to 2

12.0 hrs

Scheme rev 3 reconciliation

14 deltas vs design in 12 min • baseline ~8 hrs

7.8 hrs

14 Jan event investigation · CSO-001

Evidence pack hash-verified 19 Jan • baseline ~5 hrs

4.5 hrs

Recent Reports

Jan 2026 — Catchment D East

EPA Monthly • 01 Feb 2026 • Signed: E. Manager 15 Feb

100%

Q4 2025 — Catchment A Scheme Performance

Designed vs Delivered • 15 Feb 2026 • Signed: E. Manager

Scorecard

Jan 2026 — Catchment A

EPA Monthly • 01 Feb 2026

98%

Q4 2025 — All Sites

Council Quarterly • 15 Jan 2026

99%

14 Jan event — Catchment A CSO-001

VCAT Evidence Pack • 19 Jan 2026 • Hash-verified

Evidence

Active CSO Risk

2

Of 8 monitored points

Events in range

1

Total duration tracked

Avg Response Time

12 min

↓ 8 min improvement

Regulatory Compliance

100%

All events logged & reported

Overflow Volume (YTD)

45 kL

↓ 68% vs prior year

CSO Overflow Network

Live Monitoring

6-Hour CSO Prediction Timeline

ML Prediction

Overflow PointsClick to highlight on chart

CSO-001

Catchment A

Level 82% / Overflow in ~55 min

→ Activate upstream diversion at Catchment A Junction. Notify ops team.

CSO-004

Catchment C

Level 78% / Overflow in ~1.5 hrs

→ Monitor. Pre-position crew at Catchment C MH if level exceeds 85%.

CSO-002

Catchment M

Level 54% / Low risk

No action required

CSO-003

Catchment E

Level 22% / No risk

No action required

CSO-005

Catchment B

Level 18% / No risk

No action required

CSO-006

Catchment G

Level 35% / No risk

No action required

CSO-007

Catchment I

Level 41% / No risk

No action required

CSO-008

Catchment J

Level 28% / No risk

No action required

Root Cause Analysis

Based on 5 events in the last 12 months

12-Month RCA trend

Q2 2025

Q3 2025

Q4 2025

Q1 2026

RainfallI&I / CapacityBlockage / Trade

Capacity-driven events rising as growth outpaces augmentation — reinforces business case for Catchment A trunk uplift.

CSO Event Log — Last 90 Days

Auto-reported

Click any row to expand event details

Date	Location	Duration	Est. Volume	Peak Level	Root Cause	Receiving Waterway	Env. Impact	Regulatory Status	Post-event actions
28 Jan 2026	CSO-004 Catchment C	28 min	~45 kL	96%	Rainfall (32mm/hr)	Receiving Waterway 2	Medium	Reported	WO-4412 jetting · closed
Event Timeline 14:13 — Rainfall intensity exceeds 25mm/hr threshold 14:23 — Upstream diversion activated at Catchment C Junction 14:35 — CSO-004 level exceeds 90%, overflow imminent alert 14:41 — Overflow commenced, discharge to Receiving Waterway 2 15:02 — Rainfall easing, level stabilising at 93% 15:09 — Overflow ceased, level receding 15:42 — CSO-004 level below 50%, event closed Root Cause Narrative Rainfall event (32mm/hr peak) exceeded design capacity at CSO-004 Catchment C. Upstream diversion activated at 14:23 but was insufficient to prevent overflow. Overflow commenced at 14:41 and ceased at 15:09. Total duration: 28 min, estimated volume: 45 kL discharged to Receiving Waterway 2. Environmental impact assessed as Medium — no fish kill observed, downstream sampling within limits within 4 hours. Regulatory Submission Reported — EPA Victoria notified 28 Jan 2026 15:55 AEDT via automated submission. Ref: EPA-CSO-2026-0041 IWM Plan reference IWM Plan 2019 §4.3 — design capacity 1-in-10 ARI (27 mm/hr). Event exceeded at 32 mm/hr. Climate adaptation addendum recommended — flagged for A. Reviewer Q2 2026.
14 Jan 2026	CSO-001 Catchment A	42 min	~68 kL	98%	I&I + Rainfall	Receiving Waterway 1	High	Reported	WO-4401 I&I inspection · in progress
Event Timeline 06:22 — Sustained rainfall (18mm/hr) with elevated groundwater 06:45 — CSO-001 level rising rapidly, I&I contribution estimated 35% 07:01 — Level exceeds 90%, overflow imminent 07:08 — Overflow commenced, discharge to Receiving Waterway 1 07:33 — Peak level 98%, diversion pump activated 07:50 — Overflow ceased, crew on site for sampling 08:15 — Downstream sampling initiated Root Cause Narrative Combined event: sustained rainfall (18mm/hr for 3+ hours) with significant inflow & infiltration (I&I) contribution estimated at 35% of peak flow. Aging sewer network in Catchment A catchment has known I&I issues. Overflow commenced at 07:08 and ceased at 07:50. Total duration: 42 min, estimated volume: 68 kL discharged to Receiving Waterway 1. Environmental impact assessed as High — elevated E.coli detected downstream, public notification issued. Regulatory Submission Reported — EPA Victoria notified 14 Jan 2026 09:12 AEDT. Public health advisory issued by DHHS. Ref: EPA-CSO-2026-0028 IWM Plan reference IWM Plan 2018 §3.1 — I&I contribution assumed <15% of peak. Observed 35% — baseline needs update after Q2 rehab completion. Rectification scope under review.
22 Dec 2025	CSO-002 Catchment M	15 min	~12 kL	97%	Blockage	Receiving Waterway 3	Low	Reported	WO-4380 trade waste notice · closed
Event Timeline 11:04 — CSO-002 level rising unexpectedly (no rainfall event) 11:15 — Level exceeds 85%, blockage suspected 11:22 — Overflow commenced, discharge to Receiving Waterway 3 11:28 — Field crew dispatched 11:37 — Overflow ceased after partial blockage cleared upstream 11:52 — Crew on site, full blockage removal completed 12:10 — Level normalised, CCTV inspection scheduled Root Cause Narrative Partial blockage in upstream trunk sewer (fat/grease accumulation at MH-207) caused rapid level rise at CSO-002 Catchment M. Overflow commenced at 11:22 and ceased at 11:37 after partial clearing. Total duration: 15 min, estimated volume: 12 kL discharged to Receiving Waterway 3. Environmental impact assessed as Low — minimal flow in receiving waterway, no public access downstream. Root cause: trade waste non-compliance from upstream food premises. Regulatory Submission Reported — EPA Victoria notified 22 Dec 2025 14:30 AEDT. Trade waste investigation initiated. Ref: EPA-CSO-2025-0287 IWM Plan reference Trade waste event — not within IWM Plan scope. Referred to Trade Waste team. Root cause upstream of design envelope.
03 Dec 2025	CSO-004 Catchment C	55 min	~82 kL	99%	Rainfall (45mm/hr)	Receiving Waterway 2	High	Reported	WO-4365 capacity uplift scoped
Event Timeline 16:02 — Severe thunderstorm warning issued, BOM alert 16:18 — Rainfall intensity spikes to 45mm/hr 16:25 — CSO-004 level exceeds 90% 16:29 — Overflow commenced, discharge to Receiving Waterway 2 16:45 — All upstream diversions at capacity 17:08 — Peak level 99%, maximum discharge rate 17:24 — Overflow ceased as storm cell passes 17:55 — Level below 60%, event closed Root Cause Narrative Severe thunderstorm (45mm/hr peak intensity, 1-in-10 year event for 30-min duration) overwhelmed CSO-004 Catchment C catchment. All upstream diversion capacity exhausted. Overflow commenced at 16:29 and ceased at 17:24. Total duration: 55 min, estimated volume: 82 kL discharged to Receiving Waterway 2. Environmental impact assessed as High — significant sediment plume, downstream turbidity exceedance for 6 hours. Regulatory Submission Reported — EPA Victoria notified 03 Dec 2025 18:40 AEDT. Environmental monitoring extended to 72 hours. Ref: EPA-CSO-2025-0271 IWM Plan reference IWM Plan 2019 §4.3 — design capacity 1-in-10 ARI. 45 mm/hr is ~1-in-20 ARI for 30-min duration. Within envelope of uncontrolled peak events acknowledged in 2019 plan Appendix D.
18 Nov 2025	CSO-001 Catchment A	8 min	~5 kL	96%	Capacity	Receiving Waterway 1	Low	Pending	WO-4342 augmentation business case
Event Timeline 08:45 — Morning peak flow, CSO-001 level elevated 08:52 — Level exceeds 95% during peak demand 08:54 — Brief overflow commenced 09:02 — Overflow ceased as demand subsides 09:15 — Level normalised Root Cause Narrative Peak morning flow exceeded hydraulic capacity at CSO-001 Catchment A. No rainfall event — overflow attributed to dry weather capacity limitation in a rapidly developing catchment. Growth rate in Catchment A exceeds sewer augmentation schedule. Brief overflow: 8 min, estimated volume: 5 kL discharged to Receiving Waterway 1. Environmental impact assessed as Low — dry weather event, minimal dilution but small volume. Regulatory Submission Pending — Draft report prepared 19 Nov 2025. Awaiting internal review before EPA submission. Capital works business case for Catchment A trunk augmentation in progress. IWM Plan reference IWM Plan 2018 §5.2 — peak dry-weather capacity assumed 95 L/s. Growth now exceeds that. Capital works business case for trunk augmentation tabled to capital panel Q1 2026.

Harvesting Viability

82%

Across 6 monitored catchments

Active Monitoring Points

14

pH, conductivity, turbidity

Quality Exceedances

3

2 pH, 1 turbidity

Trade Waste Dischargers

23

8 high-risk classifications

Harvesting Saved (YTD)

1,240 kL

From viable catchments

Catchment Water Quality Map

Harvesting Viability Scores

Catchment K Industrial

SAFE — Viable for harvesting

pH7.2

Conductivity480 µS/cm

Turbidity8 NTU

Viability92%

BPEM Removal (if harvested)

TSS 86% /80

TP 48% /45

TN 47% /45

Litter 82% /70

Top Risk Factors

Seasonal turbidity spikes during heavy rainfall
One food manufacturing discharger (low risk)

Catchment G Industrial

MARGINAL — Monitor closely

pH6.1

Conductivity920 µS/cm

Turbidity12 NTU

Viability64%

BPEM Removal (if harvested)

TSS 72% /80

TP 38% /45

TN 41% /45

Litter 68% /70

Top Risk Factors

Elevated conductivity from chemical manufacturing
pH trending below 6.5 threshold
3 high-risk trade waste agreements in catchment

Catchment O Business Park

SAFE — Viable for harvesting

pH7.4

Conductivity380 µS/cm

Turbidity6 NTU

Viability95%

BPEM Removal (if harvested)

TSS 88% /80

TP 52% /45

TN 49% /45

Litter 85% /70

Top Risk Factors

Mostly logistics/warehousing — minimal chemical risk
New development may introduce unknown dischargers

Brooklyn Industrial

NOT VIABLE — Contamination risk

pH4.8

Conductivity1,540 µS/cm

Turbidity45 NTU

Viability12%

BPEM Removal (if harvested)

TSS 48% /80

TP 21% /45

TN 18% /45

Litter 54% /70

Top Risk Factors

Metal finishing operations discharging acidic runoff
Multiple non-compliant trade waste agreements
Historical soil contamination contributing to turbidity
EPA investigation active (ref: EPA-TW-2025-0891)

Water Quality Trends (7-day)

Trade Waste Impact Analysis

Future Scheme Pipeline — Catchment Screening for Harvesting i Aligned to long-term water strategy

Catchment	Viability	Area (ha)	Est. yield (ML/yr)	Nearest reuse demand	Next step
Catchment O Business Park	95%	42	8.5	Warehousing irrigation · 1.2 km	Pre-feasibility (Q3 2026)
Catchment K Industrial	92%	58	11.2	open space · 800m	Concept brief drafted
Catchment N / Catchment A Plains PSP	78%	118	22.6	New residential irrigation · integrated	PSP drainage strategy under review
Catchment G Industrial	64%	34	5.2	Trade waste too close · caution	Monitor · re-screen 2027
Brooklyn Industrial	12%	26	n/a	Contamination disqualifies	Exclude · EPA-TW-2025-0891

Portfolio outlook: Top 3 viable catchments represent 42.3 ML/yr combined harvestable yield — ~32% of the authority's stated 130 ML/yr expansion target. Pre-feasibility commissioned for Catchment O (Q3 2026). Catchment N PSP drainage strategy review opportunity flagged to E. Manager.

17/02/26 14:31:52

ROCKBANK CSO004 — STORMWATER PUMP STATION

Station Alarms

Power Supply OK

Un-Acked Alarms

Callout Active

Intrusion

Pump Trip

Fire

Rain Gauge RG-101

[GOOD] RAINFALL mm/hr 8.2

INLET

[GOOD] FIT-101 INLET FLOW 42.0 L/s

WET WELL

HH 2.80

H 2.40

L 0.60

LL 0.30

[GOOD] LIT-101 WET WELL LEVEL 2.41 m

CSO OVERFLOW RISK

DETENTION BASIN

[GOOD] LIT-201 BASIN LEVEL 0.34 m

PMP-101

TRIPPED

Mode: AUTO
Fault: THERMAL O/L
Run Hrs: 12,847

0 RPM

PMP-102

RUNNING

Mode: AUTO
Status: IN SERVICE
Run Hrs: 8,234

1420 RPM

PMP-103

STANDBY

Mode: AUTO
Status: AVAILABLE
Run Hrs: 6,102

—

XV-201
FAULT

[UNCERTAIN] FIT-301 DISCHARGE 38.2 L/s

[GOOD] PIT-301 PRESSURE 98 kPa

RISING MAIN
→ TO NETWORK

⚠ ALARMS DISABLED for CSO004 ⚠

[STALE] TIT-101 AMBIENT 28.4 °C

STATION HOURS 43,219

Tag Quality [GOOD]signal valid · within tolerance [UNCERTAIN]data out of expected envelope [STALE]last update beyond cadence threshold [BAD]sensor failure or comms loss OPC quality bits 192/68/64/0

RTU-042 TXs: 14,208 RXs: 14,186 Comms: 96.2% Bursts: 3 RspTime: 245ms Status: DEGRADED Last: 17/02/26 14:31:48

WESTERN WATER SCADA SYSTEM

Logged On User:
admin

17/02/202614:31:52

RBK — CSO004 Catchment C Pump Station

15/02/26 14:32:00 2 Days 5 Minutes / sample 17/02/26 14:32:00

Variable		Variable description	Maximum scale	S.
RBK.CSO004.PMP101.RUNNING	⚙	Catchment C PS Pump P101 Run Stat...	2	⚙
RBK.CSO004.PMP102.RUNNING	⚙	Catchment C PS Pump P102 Run Stat...	2	⚙
RBK.CSO004.LIT_101.WW_LVL	⚙	Catchment C PS Wet Well Level(m)	3	⚙
RBK.CSO004.LIT_201.DET_LVL	⚙	Catchment C PS Detention Basin Level(m)	3	⚙
RBK.CSO004.FIT_101.INLET_FLOW	⚙	Catchment C PS Inlet Flow (L/s)	100	⚙
RBK.CSO004.FIT_301.DISCH_FLOW	⚙	Catchment C PS Discharge Flow (L/s)	100	⚙
RBK.CSO004.PIT_301.PRESSURE	⚙	Catchment C PS Discharge Pressure (kPa)	300	⚙

ClearSCADA Alarm Viewer — Western Water Network [PROD-SVR02] — Operator: admin

01r

Alarms

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Alarm Rationalization...

Alarm Summary — All Areas ● UNACK: 18

OPC: CONNECTED Scan: 250ms Qual: 3 BAD Hist: 92% DISK Poll: 17/02/26 14:32:08.412

⚠ 47 STANDING ALARMS (oldest: RBK_CSO004_OVF_RISK — 14 days) — 6 shelved — 3 disabled — alarm load: 238/hr (target: <10/hr per ISA-18.2) Last rationalization: NEVER

#	Date/Time	Age	Pri	Ack	Tag Name	Description	Cond	Value	Q	Limit	Area	Source

Hover row:— select an alarm row to inspect tag address, scan rate and quality bits

Showing: 0 of 247 Emg: 0 High: 0 Med: 0 Low: 0 Rtn: 0 Chatt: 0 Horn: ACTIVE Page 1 of 3 Connected: PROD-SVR02\OPC.1

F1 Help F2 Filter F3 Find Next F5 Refresh F11 Full Ctrl+K Ack Sel Ctrl+H Silence Ctrl+S Shelve Ctrl+F Find Tag Operator akhuu (Andrew Khuu) Auth Eng I+II+III Last keystroke 14:32:08

SOE LOG 14:31:58.412 akhuu ACK RBK.PR003.PIT_301.PRESS_L 14:31:42.118 akhuu ACK RBK.PS009.PMP_101.TRIP 14:31:18.667 akhuu SHELVE RBK.RTU042.COMMS.TIMEOUT (chattering · 4hr) 14:30:55.881 akhuu COMMENT RBK.CSO004.AIT_301.SEW_LVL_HH "Storm event — diversion activated"

Asset Detail

DET-002 Overflow Risk

Asset Register

Panel