KSB drains metropolis to protect millions of inhabitants: Mexico City flood control project

Mexico City is repeatedly threatened by flooding and stormwater. Heavy rainfall creates a mixture of rainwater and waste water which floods large parts of the city. In a city district particularly affected, 1.5 million inhabitants suffered from flooding on a regular basis.

Why is that? Situated on a plateau at an altitude of about 2,200 m above sea level, Mexico City is located in a basin surrounded by mountains. The ground on which the 20-million strong metropolis stands has sunk considerably over the course of many years. As a result, it is difficult for the rainwater to drain off, which means the city is repeatedly at risk.

In order to protect the inhabitants in the long term from the threat of floods, CONAGUA, the National Water Commission, initiated the country’s largest and most significant infrastructure construction: the La Caldera pumping station with its combined sewer system for flood control. The construction was designed to ensure the draining and removing of rainwater and waste water from this part of Mexico City and the surrounding areas.

The Mexican National Water Commission CONAGUA (La Comisión Nacional del Agua) is responsible for infrastructure works all over the country – including the planning (for example of flood control projects), engineering and management in this field.

Founded in 1988, the Commission employs some 17,000 staff at its headquarters in Mexico City and maintains 25 branches in the different federal states and districts.

What was unique about this task was the sheer scale of the flood control project: a pumping capacity of 40 m3/s at a head of almost 30 metres was required – all with the highest levels of efficiency and to be completed by the tight deadline. The inhabitants needed to be protected from flooding as quickly as possible.

In addition, the customer expected special technical support, since with major projects of this kind all requirements need to be fulfilled without exception. KSB had to precisely monitor every work step and be available to provide the project managers with advice and support on site.

The design of both the pumps and sumps, which had to match the hydraulic parameters, was specially tailored for the La Caldera pumping station in close cooperation with the project management. CFD calculations and tests with physical models revealed that the very small sump diameter was still sufficient for this huge pumping station.

In October 2010, the La Caldera pumping station started operation equipped with a total of 24 Amarex KRT K submersible motor pumps. In close cooperation with KSB Mexico and KSB Halle, it was possible to deliver all required pumps and accessories while still keeping within the budget. All pumps supplied met the technical specifications 100 percent. From piping calculations with regard to torsional stresses and natural frequencies, model tests, installation and commissioning through to on-site test runs, KSB delivered excellent work and services to the full satisfaction of the customer.

KSB was also able to meet the tight delivery deadline. In order to deliver and commission the first 10 pumps within a mere 5 months and the remaining pumps in 8 months, KSB even chartered an aircraft. This allowed KSB to supply, install and put into service the submersible waste water pumps on time to safely ensure protection against flooding.

Location: La Caldera, Mexico City

Client: CONAGUA (La Comisión Nacional del Agua)

Founded: 1988

Employees: Around 17,000

Industry: Public authority

Application: Flood control

16 x Amarex KRT K submersible waste water pumps

 700-900/H 680 10 UNG-S

Q = 2000 l/s, H = 26.55 m, P = 912 HP, V = 4160 Volt

8 x Amarex KRT K submersible motor pumps 

400-630/H 340 8 UNG-S

Q = 1,000 l/s, H = 28.83 m, P = 500 HP, V = 4,160 Volt

24 control and monitoring units with the respective distribution boxes to NEMA

Capacity 40 m3/s at a head of around 30 metres

Fluid handled: Rainwater

Commissioned: 2010