Colombia thus departed from the standard concession approach, which requires private concessionaires to finance investments with their own resources.
[4] The first contracts followed mostly the mixed-ownership company model, with the municipality holding a majority of the shares but with management fully delegated to a private operator.
None of the studies showed negative impacts of water privatization on access, service quality, operational efficiency or tariff levels.
[1] Successful public utilities include EAAB in Bogotá, which made strong progress in access over the last decade, reaching universal coverage.
Cartagena achieved full water supply coverage despite a 50 percent jump in the size of its population during the same period, largely due to the arrival of poor rural migrants.
To achieve universal coverage, the operator in Cartagena made extensive use of community bulk-supply schemes that provide safe water to the many illegal settlements that were expanding on the city's periphery.
The company Conhydra in the department of Antioquia achieved full water coverage within a few years in the towns of Marinilla, Santafe, and Puerto Berrio (combined population 170,000) starting from levels of 80 – 90 percent.
Strong gains were made in Montería, Tunja, Marinilla, and Palmira, but the reduction was modest in Cartagena, Barranquilla, and Santa Marta, and no progress was achieved in Girardot or Soledad.
At the same time, the average tariff was halved in real terms, suggesting that a significant portion of the savings achieved through efficiency gains was passed to customers.
Colombian construction companies that were active in the water sector were awarded PPP contracts following tenders in which only local investors participated.
In all these cases, governments chose to ease prequalification criteria to increase competition, resorting to various mechanisms to ensure the winning bidder would be able to operate the water utility.
AAA earned the trust of its customers and political support by going to the poorest neighborhoods, interviewing thousands of people with the goal of understanding their expectations and assumptions regarding water and sanitation.
The company then conducted a massive communications campaign with more than 40 staff, many of them social workers by profession, to work full-time in community outreach.
Simultaneously, AAA adopted an aggressive external relations strategy that contrasts sharply with the cautious, low-profile approach preferred by water companies in many other Latin American cities.
According to company officials, this approach relieved most consumers’ anxiety about the water meter and encouraged them to start monitoring their own consumption.
As a result, AAA has established partnerships with virtually all of Barranquilla's pawnshops that enable people to pay their water bill while conducting other transactions.
Similar partnerships allow customers to pay their water bills at banks, department stores, grocery chains, and sports clubs through the city.
To ensure that cutoffs are short-lived, every month AAA billing agents set up portable, outdoor "payment stations" in low-income neighborhoods.