Water distribution in Mexico:
the Aguascalientes experience

Context and stakes

Mexico is notorious for its over-exploitation of between 50 and 100% of available natural resources. The World Bank has identified 80 aquifers of the largest cities which are serious threatened. The initiatives launched in Aguascalientes (Mexico's first franchise, signed in October 1993) aim to reduce, or even to resolve the serious problem of the continuing fall (4/5 metres per year) in the levels of the aquifer of a city of 800,000 inhabitants which is growing at a rate of 3-4% per year, with no other resource to replace it.

Objectives of the action

— To study the management of the aquifer: to ensure rational management, compatible with the resources available and to reduce the over-exploitation of the aquifer.

— To test the sectorisation of the networks: to help to reduce demand and to improve the service offered to the inhabitants.

— Charging: to find a charge rates system suited to households' financial means.

— To set up a social aid fund: to help the poorest families who cannot pay for their water consumption at the minimum rate (without going so far as to make it free).

Description of the action

— Aquifer study: Fact: the aquifer has fallen by 150 metres since 1960 without any measures being taken to prevent this. Action stages: synthesising and analysing over 100 previous studies carried out on the Aguascalientes valley aquifer (with no decision being taken); devising a aquifer management tool (mathematical model) and arranging how it is used

improving and increasing the city's water production (building catchment areas outside the urban area); establishing a regulatory framework on using underground water (institutional approach); defining technical specifications for drilling boreholes.

— Sectorisation: Fact: a very high volume of water is lost in the network (65% of production). Action stages: analysing the quality of metering and locating pirate connections; setting up hydraulic distribution sectors in which incoming volumes are metered; finding non visible leaks and repairing them; assessing the overall hydraulic situation to quantify the reduction in water loss

— Charging : defining 3 socio-economic levels in the city; establishing a charge rate for each.

— Setting up a social fund: defining the needs of this fund and where its resources are to come from; rules to be applied for allocating this financial aid to settling bills

Responsibilities of each actor:

— The aquifer study is collegiate. It is directed by a French engineering practice, Burgeap, in association with: the state head of the CNA, the State of Aguascalientes, the municipality, the university students and the franchise holder responsible for initiating the programme.

— Thanks to sectorisation a communication project has developed with the population and their participation can be requested: refraining, for example, from consuming any water during night-time rates of flow measurements.

— Charging: the franchise holder must ensure that the equation is properly applied: economic level = corresponding charge rate.

— Social aid fund: the regulatory organism must ensure, without political pressure, that the rules for allocating this aid to the poorest clients are correctly applied.

Results

— Aquifer: the experiment is ongoing, nevertheless the productive participation of the Mexican authorities is to be noted.

— Sectorisation: the number of leaks discovered, using the methodology which will be described elsewhere, is approximately 50 leaks per night, which makes an increase of 15 to 20% in the output of the network seem likely within 2/3 years (i.e. an increase from 50 to 65/70%).

— Charging: thanks to a carefully considered charging system, matching subscribers' financial possibilities, complemented by a marked improvement in service, the rate of recovery for 1997 has been consolidated, and stands at over 88%.

— Social aid fund: all of the funds available have been allocated, which has contributed to the debt recovery rate mentioned above.

Strong points of the experience:

— Aquifer: ongoing.

— Sectorisation: training young Mexican engineers in this technology. The positive attitude and the participation of the inhabitants of the neighbourhood, which is of great help to the staff, working essentially at night.

— Charging: ensuring that the socio-economic levels are correctly applied.

— Social aid fund: the inhabitants' excessive enthusiasm for this subsidy, boosted by the politicians craving for popularity which tends to deflect the way the funds for this aid are used from its original purposes.

Problems / lessons learned:

— Sectorisation: l the major discovery of anomalies and the advanced state of wear and tear of the hydraulic installations (poor quality materials, defective repairs) l thanks to the level of detail of our investigations, we now have a precise understanding of replacement needs and where they are located. Investments can therefore be accurately targeted.

— Social aid fund: the need to ensure that the rules for allocating the aid subsidies are rigorously applied.

Perspectives and impacts

These ongoing experiments have been used for the first time in Mexico City and launched on a modest scale in other cities.

Sustained efforts will need to be made to overcome the authorities' fears that any responsibilities for failures might be exposed and the technocratic environment, and to give these experimentations a firm foundation.

Contacts Jacques Coutelle, Director of Omsa (ICA/CGE), CGE representative in Mexico,176 Calle Tomas Alva Edison, Col. San Rafael Mexico D.F., C.P. 06470 Mexico City (Mexico). Tel.: (52) 5 722 77 50. Fax: (52) 5 722 77 09.Manuel Reed, Managing Director, CCAPAMA, Dr Salvador Quezada Limon 1407, Col. Curtidores, 20060 Aguascalientes, Ags (Mexico). Tel.: (52) 49 15 15 13. Fax: (52) 49 16 97 28.

Possible courses of action 6, 7, 8 and 9

Localisation: Aguascalientes, located 450 km north-west of the Mexico City
Domain of intervention: integrated resource and distribution management
Area of intervention: urban areas (sectorisation/tariff setting: Aguascalientes conglomeration), rural areas (aquifer study: Aguascalientes water valley)
Donors: the aquifer study is funded by the Fasep of the French Ministry of the Economy and Finance, the franchise holder CAASA is responsible for the sectorisation of the drinking water network
Duration: ongoing