Sound urban water management within the metropolitan area of the Aburrá Valley is carried out by a set of technically strong institutions with financial independence—and lack of political interference [2] such as Empresas Publicas de Medellin (EPM).

[3] The metropolitan area of the Aburrá Valley is located near the equator but with a high elevation, the average climate is quite mild without great variation in temperature and rainfall.

[2] Adequate supply and good resource management has allowed nearly 100% of MAM citizens across ten municipalities to receive piped water.

[2] For many years leading up to the early 1990s, Medellín had been growing rapidly as large quantities of people moved into the Metropolitan Area of the Aburrá Valley in hopes of taking advantage of economic opportunities.

In order to confront the deteriorating sanitary and environmental conditions, as well as their adverse effects on resident's health and well-being, the Medellín River Sanitation Program was approved in the 1980s.

[4] By most of the initial criteria, the program was successful and propelled Medellín into becoming recognized as a strong example of urban water management.

The physical results (i.e. new treatment plant, aqueducts, wastewater collectors, new conveyance pipes) were all very successful; the performance of EPM has been highly satisfactory.

Apart from fewer than expected negative results from the program, Medellín has become a successful example of good practice in urban water management.

This interception of multiple geographical, economic and social stressors constitutes a major challenge to extending water services to these areas.

[5] That being said, a 2005 Report of the Economic Colombian Review of Proexport and the International Cooperation Agency of Medellín concluded that the Aburrá Valley, where Medellin is located, is the top economy in the state with a GDP of USD 7.8 billion in 2005.

[3] A “North Interceptor” tunnel will be built six feet under the Medellín River with a length of 8 km and will transport water to the future treatment plant in the municipality of Bello.

A stormwater plan in concert with flood plain management developed by all the relevant institutions can help to address the overall basin with an integrated solution.

Increasing urbanization results in greater land degradation and fewer permeable surfaces both of which precipitate growing drainage problems.

Population growth coupled with urbanization had turned the Medellín River into a dump site for millions of tons of municipal household waste.

Untreated household wastewater accumulated in these streams and they became an open sewer, threatening residents’ health, the aesthetic conditions of the city, and the quality of life in the Aburrá-Medellín valley.

EPM is a public-sector entity that works like a private company and performance is measured by efficiency indicators that are comparable to other successful international water operators.

ESP has two fundamental pillars: 1) The strengthening of the local recycling networks; and 2) informal education that addresses how/whom is generating waste.

Environmental authorities that guarantee the renewability of water make use of this compensatory tax to cover expenses related to carrying out their responsibility.

The Law incorporates users’ participation in design, building, and posterior operation and maintenance (O&M) by establishing a water fee which includes a fraction of the total costs.

The plan is composed of the following items: i) design and construction of sewerage in the Girardota municipality; ii) design and construction of sanitation interceptors for the Medellín River in the Caldes municipality; iii) cleanup of small tributaries in the Aburra-Medellín valley through proper handling of domestic wastewater using unconventional systems in areas where collection is difficult; iv) implementation of channel stabilization; v) cleaning water channels and improving water quality in the Aburra-Medellín valley; and vi) improvement of hydropower capacity on the river by removing sediment in reservoirs.

In the most recent phase, the bank approved a 25-year loan to Colombia in February 2009 for US$450 million for a cleanup project of the Medellín River.

This is the largest loan the bank has ever issued for a river cleanup and will be used to build a treatment plant in the northern end of the Aburrá-Medellín valley.

In a prior phase, a loan of US$130 million was used to build the San Fernando wastewater treatment plant in the southern end of the Aburrá-Medellín valley.