Urban Drainage & Water Systems: Key Infrastructure

Urban Drainage Master Plans

A master plan involves a set of studies for the planning of urban drainage in a city (study area) over a period of time, considering its interaction with external contributing basins and receiving streams. These plans are designed to maintain hydraulic order.

Drainage System Components

A drainage system typically includes:

• The main collector and its discharge works to a main channel or another collector.
• Branches and tributaries.
• Inspection and cleaning chambers.
• Sinks (inlets) that capture runoff from roads, e.g., Zanjón de la Aguada.

Collectors can be in open channels or underground.

Key Hydraulic Structures

Dams and Reservoirs

A reservoir is a body of work consisting of a dam that closes a natural channel. An embankment dam is a common type.

A cofferdam is a temporary dam that diverts water through a pipe to allow for construction in a dry area.

Channels and Plinths

A channel for traditional irrigation of crops consists of intakes that control the passage of water from the river to the canal. Tertiary canals deliver water to individual farms.

Plinths are anchored reinforced concrete structures with stirrups, upon which screens rest.

Bank Protection Works

Bank protection works are crucial for maintaining waterway stability:

• Longitudinal Defense: Utilizing natural rocky slopes.
• Piers: Structures designed to divert runoff, allowing heavy materials to decant.
• Retaining Walls: Walls designed to stop heavy materials (e.g., 500kg rocks) and protect structures.

Categories of Water Management Works

Water Supply Works

These works supply water to populations and industries, facilitate irrigation, and maintain the water table.

Works Utilizing Water's Energy Potential

This category includes various types of waterfalls for energy generation and works for navigation.

Defense Works

These encompass flood control reservoirs and the correction and protection of natural waterways.

Repair and Improvement Works

Examples include drainage and sewage treatment systems, as well as reservoirs and streams managed for fishing, recreation, or landscape enhancement.

Specific Hydraulic Structures & Systems

Gabions

Gabions are frames of wire mesh, typically filled with stones instead of soil. The intrinsic flexibility of a gabion's cage allows it to function effectively without breaking.

Dams and Spillways

A spillway is a lateral longitudinal opening constructed in one of the side walls of a channel to drain excess flow.

Water Collection Systems

A typical water collection system consists of:

• The intake
• The adduction channel
• The sedimentation tank or sand trap

River Intakes

For stable river beds and high-volume streams and estuaries, various intake methods are used:

Pipe Intakes

A pipe is extended a certain distance from the shore, submerged so it never runs dry, with its end directed downstream.

Tower Intakes

For large-scale projects, a tower features entrances at different levels controlled by gates, with an exit onto the shore.

Bank Intakes

When the river has an almost vertical bank of hard material (rock), water can be captured directly from the same side.

Conduits and Pumping Systems

Conduits are pipelines for transporting water from a regulating reservoir or intake pool. Water transport can occur in two ways: by gravity or by pumping.

Pumping systems are necessary when the water source (e.g., a pond) is at a lower elevation than the point of distribution or further collection, requiring mechanical lift pumps.