Invisible
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SYSTEM 02 / From source to tap, and back

Water

Trace the water you use through treatment, pressure, pipes and the often-forgotten return journey.

THE SYSTEM MAP

Follow the flow.

A managed water journey

This conceptual route follows source water through selected drinking-water treatment stages, distribution, sewers, wastewater treatment and discharge or reuse. Intermediate filtration, pumping and storage are omitted from this short route and explained in the component guide below. These are connected stages, not a single pipe or a universal treatment design. Select a component to inspect it.

INSIDE THE SYSTEM

Catchments & source water

A water supply begins with a landscape, an aquifer or another source whose condition shapes everything downstream.

Explore this component
Read the diagram as text
  1. Catchments & source water — A water supply begins with a landscape, an aquifer or another source whose condition shapes everything downstream.
  2. Coagulation & clarification — Tiny suspended particles are gathered into larger clusters so that the plant can separate them from the water.
  3. Disinfection & monitoring — Disinfection inactivates susceptible microorganisms; monitoring checks that the wider treatment system is working.
  4. Distribution & the tap — Pipes, valves, service connections and building plumbing deliver treated water while preserving its quality.
  5. Sewers & lift stations — A collection network carries used water from buildings toward treatment, using gravity where possible and pumps where needed.
  6. Wastewater treatment — Physical and biological processes remove or transform pollutants before water is released or treated further for a particular reuse.
  7. Discharge & water reuse — Treated water may return to the environment or serve another use, with requirements matched to that destination.

This conceptual route follows source water through selected drinking-water treatment stages, distribution, sewers, wastewater treatment and discharge or reuse. Intermediate filtration, pumping and storage are omitted from this short route and explained in the component guide below. These are connected stages, not a single pipe or a universal treatment design.

Turn a tap and a managed water journey becomes visible for a few seconds. Before that moment, source protection, treatment, pumping, storage and distribution have worked together. Afterwards, sewers and wastewater plants may carry the journey onward. The system moves material, uses energy and depends on information as well as pipes.

This family follows a conceptual urban system with a treated surface-water supply and central wastewater collection. It is a teaching map, not a local network drawing. Groundwater supplies, desalination, onsite sanitation and reuse arrangements differ; the component pages explain those variations without making one country’s process universal.

Read the main path to stay oriented, inspect a component for its mechanism, or take a guided journey from an everyday action. The pump-outage scenario isolates one idea: storage buffers a mismatch between inflow and demand. Its chosen numbers do not predict a real city’s service or water quality.

ONE ACTION, STEP BY STEP

Choose your way in.

THE COMPONENT FIELD GUIDE

Meet the parts that make it work.

Water

Catchments & source water

A water supply begins with a landscape, an aquifer or another source whose condition shapes everything downstream.

Water

Coagulation & clarification

Tiny suspended particles are gathered into larger clusters so that the plant can separate them from the water.

Water

Filtration & membranes

A filter separates selected contaminants from a water stream, but its capabilities depend on its material and design.

Water

Disinfection & monitoring

Disinfection inactivates susceptible microorganisms; monitoring checks that the wider treatment system is working.

Water

Pumps & pressure zones

Pumps supply energy that helps water climb, overcome losses and reach the pressure needed within a supply zone.

Water

Treated-water storage

A service reservoir or tank holds treated water so that production and demand do not have to match at every moment.

Water

Distribution & the tap

Pipes, valves, service connections and building plumbing deliver treated water while preserving its quality.

Water

Sewers & lift stations

A collection network carries used water from buildings toward treatment, using gravity where possible and pumps where needed.

Water

Wastewater treatment

Physical and biological processes remove or transform pollutants before water is released or treated further for a particular reuse.

Water

Sludge, digestion & biogas

Treatment concentrates some material into a solids stream that needs its own processing, safeguards and destination.

Water

Discharge & water reuse

Treated water may return to the environment or serve another use, with requirements matched to that destination.

Water

Metering & water losses

A water balance separates useful consumption, physical leaks and measurement errors so that the right problem can be addressed.

Water

Water-quality sensing

Instruments and samples help operators recognise changes, investigate causes and verify that protective barriers are performing.

Water

Desalination & concentrate

Desalination separates a less saline water stream from a saltier stream, adding a supply option with energy and environmental dependencies.

Water

Stormwater & urban surfaces

The surface of a city changes how quickly rain runs off, what it carries and which drainage or treatment system receives it.

02
Water / Storage & resilience

How long can stored water bridge an outage?

Interactive model

Change outage duration and water demand while a fictional reservoir receives no inflow. Compare two assumptions about the same 600 m³ store.

A reservoir buying timeDrawing on storage
PUMP OFFLINEUSABLE STORAGE OVER TIME 600 m³ initial 400m³ remaining 0 inflow100 m³/h demand 6003000 0612 h Empty after 6 h at 100 m³/hELAPSED 2 h · VOLUME BALANCE, NOT A PRESSURE FORECAST
Baseline: 600 m³ usable storage · 100 m³/h demand · no inflow

A reservoir buying time

Scroll or use the arrow keys to explore the enlarged diagram. Close with the button or Escape. Baseline: 600 m³ usable storage · 100 m³/h demand · no inflow.

01 / Change the inputs
2hours
0 h12 h

How does demand change the amount of time a fixed store can bridge?

100m³/hour
50 m³/hour200 m³/hour

The usable store stays at 600 m³. A higher withdrawal rate uses the same volume sooner.

02 / Read the responseSince the pump stopped: 200 m³ delivered. Full-store buffer: 6 h, compared with 6 h at the starting demand.
Usable volume
400m³
Volume buffer
4hours
Unmet volume
0m³
400 m³ of usable storage remain

Demand removes 100 m³ each hour while the pump supplies nothing. At hour 2, 400 m³ remain: 4 more hours at this assumed demand. Storage volume alone cannot establish pressure or water quality.

03 / Compare A and B

TWO INPUTS. TWO CONDITIONS.

Pin the current settings as A, then change either input to test B. A stays in memory only while this page is open. Shared links include the current B inputs, never the pinned A.

No A is pinned. Enable the interactive controls, choose settings and pin them to compare.

Compare both inputs and the model response. A stays fixed until you replace or clear it; B follows the controls.
Setting or resultA · Not pinnedB · Current
Time without pump inflow—2 hours
Water demand—100 m³/hour
Usable volume—400 m³
Volume buffer—4 hours
Unmet volume—0 m³
Inside the modelAssumptions, limits & sources

Conservation of water connects inflow, outflow and the change in storage. At the starting demand of 100 m³/h, 600 m³ lasts six hours with no inflow. At 200 m³/h it lasts three hours. Pin a scenario before changing demand to compare these assumptions directly; neither result predicts service at a particular tap.

  • The chosen starting usable storage is 600 m³. This is an editorial teaching value, not a measured or typical reservoir.
  • Pump inflow is zero throughout the selected interval. Requested demand is constant within each scenario and can be set from 50 to 200 m³/h; its starting value is 100 m³/h.
  • Remaining usable volume = max(0, 600 − demand × elapsed hours). Unmet volume = max(0, demand × elapsed hours − 600). Total storage duration = 600 / demand.
  • Remaining volume buffer = max(0, 600 / demand − elapsed hours). No alternate supply, leakage, evaporation or changing demand is included.
  • Storage is assumed deliverable until its usable volume reaches zero. Real pressure can become inadequate before a tank is empty. No water-quality or pressure calculation is performed.
  • The references explain real storage, pumping and pressure dependencies. The selected values and calculated durations are original illustrative arithmetic, not operational standards.

Model references: Sydney Water: Water System Planning Guideline · US Environmental Protection Agency: How to Conduct a Sanitary Survey of Drinking Water Systems · US Environmental Protection Agency: Protecting Water Quality Through Distribution System Pressure Management

SYSTEMS WITHIN SYSTEMS

Keep following the connections.

Sources & further reading

Original explanations informed by these sources. Diagrams are conceptual; local systems differ.

  1. Basic Information about Source Water Protection US Environmental Protection Agency · Not stated · Source & rights record
  2. Groundwater Flow and the Water Cycle US Geological Survey, Water Science School · 2026-09-17 · Source & rights record
  3. Water safety planning World Health Organization · Not stated · Source & rights record
  4. 8.3.2 Coagulation and flocculation Australian National Health and Medical Research Council · Not stated · Source & rights record
  5. Surface Water Treatment: Optimization, Training and Other Resources Oregon Health Authority · Not stated · Source & rights record
  6. Water treatment Seqwater · Not stated · Source & rights record
  7. Drinking Water Treatment Plant Residuals Management: Technical Report US Environmental Protection Agency · 2011-09 · Source & rights record
  8. How Water Treatment Works US Centers for Disease Control and Prevention · 2026-11-10 · Source & rights record
  9. Overview of Drinking Water Treatment Technologies US Environmental Protection Agency · Not stated · Source & rights record
  10. About Water Disinfection with Chlorine and Chloramine US Centers for Disease Control and Prevention · 2026-11-10 · Source & rights record
  11. Drinking Water Disinfection Washington State Department of Health · Not stated · Source & rights record
  12. Water System Planning Guideline Sydney Water · 2014-09 · Source & rights record
  13. Water Pressure Management Program Sydney Water · Not stated · Source & rights record
  14. Protecting Water Quality Through Distribution System Pressure Management US Environmental Protection Agency · 2021-12 · Source & rights record
  15. Protecting Water Quality Through Water Age Management US Environmental Protection Agency · 2022-04 · Source & rights record
  16. How to Conduct a Sanitary Survey of Drinking Water Systems US Environmental Protection Agency · 2019-08 · Source & rights record
  17. Drinking Water Distribution System Tools and Resources US Environmental Protection Agency · Not stated · Source & rights record
  18. Where your sewage goes Melbourne Water · 2023-05-09 · Source & rights record
  19. Municipal Wastewater US Environmental Protection Agency · Not stated · Source & rights record
  20. Primer for Municipal Wastewater Treatment Systems US Environmental Protection Agency · 2004-09 · Source & rights record
  21. How wastewater is treated Water Corporation, Western Australia · Not stated · Source & rights record
  22. Eastern Treatment Plant Melbourne Water · Not stated · Source & rights record
  23. Basic Information about Sewage Sludge and Biosolids US Environmental Protection Agency · Not stated · Source & rights record
  24. Primary treatment of sewage and anaerobic treatment of sludge Melbourne Water · 2016-05-25 · Source & rights record
  25. Basic Information about Water Reuse US Environmental Protection Agency · Not stated · Source & rights record
  26. Recycled Water for Drinking: An Overview US Centers for Disease Control and Prevention · 2026-11-10 · Source & rights record
  27. Water Audits and Water Loss Control for Public Water Systems US Environmental Protection Agency · 2013-07 · Source & rights record
  28. WUE: Leakage and Water Loss Washington State Department of Health · Not stated · Source & rights record
  29. Leak Detection and Flow Monitoring Devices US Environmental Protection Agency, WaterSense · Not stated · Source & rights record
  30. Online Water Quality Monitoring Resources US Environmental Protection Agency · 2026-09-21 · Source & rights record
  31. Online Water Quality Monitoring in Distribution Systems US Environmental Protection Agency · 2018-04; second release 2019 · Source & rights record
  32. Exploratory Analysis of Time-Series Data to Prepare for Real-Time Online Water Quality Monitoring US Environmental Protection Agency · 2016-11 · Source & rights record
  33. Desalination in South East Queensland: Fact Sheet Seqwater · 2023-12 · Source & rights record
  34. How does water desalination work? Water Corporation, Western Australia · Not stated · Source & rights record
  35. Desalination U.S. Geological Survey, Water Science School · Not stated · Source & rights record
  36. Volume 1: Survey of Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems Lawrence Berkeley National Laboratory and U.S. Department of Energy · 2016-10 · Source & rights record
  37. Sources and Solutions: Stormwater US Environmental Protection Agency · Not stated · Source & rights record
  38. About Green Infrastructure US Environmental Protection Agency · 2026-09-11 · Source & rights record
  39. Green Infrastructure and Groundwater Protection US Environmental Protection Agency · 2026-02-10 · Source & rights record