Global Cities Development

Sectors

Water, sanitation & circular economy

How water, sanitation and waste are held as two utilities, each a company of its own at the sector-delivery layer, why the tariff regime sits outside them, and why the two are planned as one resource system rather than two procurements.

Overview

Water decides where a city can be built and how large it is allowed to become. Available supply, treatment capacity and the drainage behaviour of the site are constraints on the master plan, not services fitted to it afterwards. The same is true of waste: the land needed for treatment works, transfer stations and buffer zones has to be reserved while it is still unbuilt and inexpensive.

Water and waste are treated as one sector because the outputs of each are inputs to the other. Treated effluent has industrial and agricultural uses; organic waste yields material and energy; an industrial tenant’s by-product can be another’s feedstock. Designed together, these flows reduce both the volume abstracted and the volume disposed of. Designed separately, they become two problems and two sets of infrastructure.

Because a utility serves everyone in the city and cannot be interrupted, the arrangements that matter most are the ones agreed before construction: the licence, the tariff basis, the asset ownership and the step-in rights if performance fails. Those belong to the structure, not to an operating contract negotiated years later under pressure.

Schematic

The parts and how they connect

Schematic of a water cycle: abstraction, treatment, trunk main, distribution and reusePlan-style schematic. A source water body to the north-west feeds an intake and three treatment basins. A heavy trunk main carries treated water east and south into a distribution grid with metered nodes. A dashed return line runs west along the south edge to a resource-recovery block, and from there back up to the treatment works.PLATE 07 / 10SCHEMATIC · NOT TO SCALE0102030405Schematic of a water cycle: abstraction, treatment, trunk main, distribution and reusePlan-style schematic. A source water body to the north-west feeds an intake and three treatment basins. A heavy trunk main carries treated water east and south into a distribution grid with metered nodes. A dashed return line runs west along the south edge to a resource-recovery block, and from there back up to the treatment works.PLATE 07 / 10SCHEMATIC · NOT TO SCALE0102030405Schematic of a water cycle: abstraction, treatment, trunk main, distribution and reusePlan-style schematic. A source water body to the north-west feeds an intake and three treatment basins. A heavy trunk main carries treated water east and south into a distribution grid with metered nodes. A dashed return line runs west along the south edge to a resource-recovery block, and from there back up to the treatment works.PLATE 07 / 10NOT TO SCALE0102030405
  • 01Source water body and abstraction
  • 02Treatment works and basins
  • 03Trunk main and control valve
  • 04Distribution network and metering
  • 05Reuse and resource recovery
  • Source to treatment, distribution and reuse
Illustrative. Schematic of a water cycle: abstraction, treatment, trunk main, distribution and reuse. Not a site plan or a design, and not a depiction of any existing or planned facility.

What this covers

Scope of work in water, sanitation & circular economy

In the structure

How the sector is held

Water, sanitation and waste are normally delivered through two companies at layer 4 — a water and sanitation utility and a waste and resource recovery company — each with its own licence, asset register and tariff basis. The master developer at layer 3 fixes catchment boundaries, drainage and the land set aside for treatment works and transfer stations before plots are sold. Day-to-day service passes to layer 6, where operations and maintenance are held. The crosscutting digital layer carries metering, plant telemetry and billing, so that consumption data is held by the city's own structure rather than by whoever supplied the meters.

The layers of building a city

Partners and capital

How partners and capital enter

Operators enter under service or concession agreements at the level of the utility company, with performance obligations and asset-handback conditions fixed in advance. Development finance institutions treat water and sanitation as a long-dated regulated activity, which means the decisions they examine are structural: who sets the tariff, who owns the assets, who carries drought and demand risk, and what happens if an operator fails. The tariff regime itself belongs to the enabling framework at layer 1, outside the delivery company, so that the body setting the price is not the body earning from it.

Crosscutting

Sustainability and resilience in water, sanitation & circular economy

Circularity here is an engineering arrangement rather than a stated ambition: treated effluent is specified for irrigation and industrial cooling, organic waste is directed to treatment that recovers material or energy, and industrial by-products are matched to tenants that can use them. Demand management, leakage control and protection of the catchment are treated as capacity, because a litre not lost is cheaper than a litre produced. Drought and flood scenarios are tested at planning stage, and discharge, resettlement and community water access follow the environmental and social standards applied by development finance institutions.

Related

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