Integrated Water and Sewer Master Plan for Quito, Ecuador

Client: Empresa Metropolitana de Agua Potable y Alcantarillado de Quito (EMAAP-Q)
Location: Quito, Ecuador

Hazen and Sawyer was selected through international competition by the Empresa Metropolitana de Agua Potable y Alcantarillado de Quito, the local municipal water and sewer company, to update the 1997 Water and Sewage Master Plan for the Metropolitan District of Quito.

Project Outcomes and Benefits

  • The updated master plan will adjust the water and sewer short, medium, and long-term service development strategy to assist the EMAAP-Q in the operation and planning of its vital services in the District.
  • The study includes four phases - Phase1: Basic Studies and Diagnosis, Phase2: Development of Alternatives, Phase 3: Master Plan Formulations, and Phase 4: Design of Prioritized Works.

Quito’s rivers are highly affected by wastewater discharge and stormwater runoff. The projects proposed under the master plan are part of the Decontamination Plan to improve water quality.

Quito’s natural topography allows for the transfer of water and wastewater almost exclusively through gravity.

Quito has a combined sewer system which handles both wastewater and stormwater. The sanitary sewer collection system has a total length of approximately 450 kilometers, ranging in size from 600 mm to 2,700 mm.

The alternatives developed in the master plan seek to utilize owner capital efficiently though the optimization of existing water and wastewater infrastructure.

Currently, wastewater in Quito discharges into various streams without being treated. The master plan aimed to improve the level of wastewater conveyance to facilitate wastewater treatment and improve environmental water quality.

In Quito there are two climatic seasons, dry and wet. The wet season begins in October and ends in May. When the city experiences a rain event, the sewer system is greatly affected due to it being of combined type. The Master Plan took into consideration the seasonal variation in flows entering the sewage system when designing the proposed wastewater infrastructure.

Point sources are major contributors to the environmental water quality issues facing Quito. The wastewater infrastructure planned for the years 2020-2040 will be designed with enough capacity to collect all existing and projected wastewater loads and eliminate wastewater discharges like the one above.

Due to increasing population, Quito’s water demand is projected to surpass water production in the coming years if the issue is not addressed. The master plan has recommended the works necessary to satisfy potable water demand in Quito through the year 2040.

The Capital City of Quito, Ecuador, is considered a World Cultural Heritage Site for its treasures of colonial churches, paintings, sculptures, and carvings. The history of Quito stretches far beyond the arrival of the Spaniards in 1534, as confirmed by a recent discovery of archeological sites that date back to 1500 B.C.

Quito is nestled within the Andes mountain range, extending along the Eastern side of the Pichincha volcano in a narrow valley located around 2700 meters above sea level. The city is long and thin, with an approximate length of approximately 35 kilometers and a width of 3-5 kilometers.

The geographical conditions of the zone give place to a number of ecosystems; thus Quito’s surrounding areas offer a diversity of amazing landscapes, each with unique flora and fauna. Several other volcanoes are also part of the landscape of Quito’s surroundings.

The area’s unique geography offers challenges and opportunities for the provision of water and wastewater services to a population of close to 2 million inhabitants settled in the urban and surrounding areas of Quito (Metropolitan District of Quito – DMQ). The population in the DMQ is expected to grow to 4 million by the year 2040.

The existing water supply system has an installed capacity of 9.65 m3/s through an elaborate system of water intakes, transmission lines, 10 treatment plants, and a 2,080-kilometer distribution network that includes 180 reservoirs and an equal number of pressure zones. The sewer system is of a combined type, for domestic wastewater and stormwater. The total area drained is approximately 260 square kilometers. The principal network of gravity collectors has a total length of 450 kilometers ranging from 600 mm to 2,700 mm, in addition to 2,850 kilometers of secondary collectors.

Both the water supply and wastewater systems take advantage of the natural topography for gravity water transmission and distribution and to generate hydroelectricity. The existing water treatment plants are facilities that make use of appropriate conventional technologies.

Hazen and Sawyer was selected through international competition by the Empresa Metropolitana de Agua Potable y Alcantarillado de Quito (EMAAP-Q), the local municipal water and sewer company, to update the 1997 Water and Sewage Master Plan for the DMQ. The purpose of the updated master plan is to adjust the water and sewer short, medium, and long-term service development strategy to assist the EMAAP-Q in the operation and planning of its vital services in the DMQ. The study was developed in phases: Phase1: Basic Studies and Diagnosis, Phase2: Development of Alternatives, Phase 3: Master Plan Formulations and Phase 4: Design of Prioritized Works.

For more information on this project, or to discuss a similar project in your area, contact

Fernando Chiriboga, Latin America Operations Manager, at fchiriboga@hazenandsawyer.com