LAKE TITICACA BASIN (BOLIVIA, PERU)

General context 

Lake Titicaca is a region of mystery and legend. Originally inhabited by the Urus, a people today extinct, it was dominated successively by Aymara warlords, Quechuas of the Inca empire, and Spanish conquerors. Along its banks flourished the Tihuanacu culture (1,500 A.C.) that left behind immense megalithic constructions and complex agricultural systems redolent of an advanced civilization. Before it mysteriously disappeared, its art, culture and religion had spread throughout the entire Andean region.

Location and major physical characteristics

At 14 degrees south, the Andean ridge is divided into an Eastern and a Western part. Between them is a closed hydrological system of approximately 140,000 square kilometres (km2) located between 3,600 and 4,500 metres above mean sea level (a.m.s.l.). Within that system lie four major basins: Lake Titicaca (T), Desaguadero River (D), Lake Poopó (P), and Coipasa Salt Lake (S). These four basins form the TDPS system of which the main element, Lake Titicaca (8,400 km3), is the largest in South America, the highest navigable lake in the world, and according to Inca cosmology, the origin of human life.

Three geographical units can be distinguished within the system:

• the mountain ridge, with altitudes greater than 4,200 metres a.m.s.l.;

• slopes and intermediate areas, ranging inaltitude between 4,000 and 4,200 metres a.m.s.l.;

• the high plateau, from 3,657 to 4,000 metres a.m.s.l., in which Lake Titicaca is located.

The source that feeds the lake, situated to the north, belongs mostly to Peru. Of the five major rivers flowing into the lake, four run through Peruvian territory. The southern part of the system, which belongs to Bolivia, is dryer and ends in the Coipasa Salt Lake, which is formed by the evaporation of overflow from Lake Poopó.

The climate within the TDPS system is that of a high mountain region with a tropical hydrological regime of great interannual irregularity. Most extreme events in the TDPS system are related to flood risk conditions around Lake Titicaca, drought in the central and southern parts of the system and the incidence of hail and frost throughout.

Precipitation varies between 200 and 1,400 millimetres (mm), with maximum values at the centre of the lake. To the north and the south the system shows zones of diminishing humidity, from humid around Lake Titicaca, to semi-arid around Lake Poopó, to arid in the Coipasa Salt Lake area. There are great seasonal variations, as the area has typically wet summers and dry winters, with a rainy period from December through March and a dry period from May through August. The air temperature varies from -10 to 23°C. Humidity is low throughout the system. The area also receives strong solar radiation, which explains the intense evaporation that occurs in Lake Titicaca.

There are four types of land in the Lake Titicaca basin, as shown in the table below.

Major socio-economic characteristics

A population struggling with poverty

The conditions of structural poverty in the zone are such that the struggle to survive takes precedence over anything else.
Education is therefore not a priority. The illiteracy rate is 22 percent and is differentiated by area and gender. t is higher in rural areas than in cities, and within rural areas, it is higher for females.
Health problems in the TDPS system are clearly related to endemic poverty and, by extension, to such attendant problems as poor nutrition, lack of clean water and sanitation, a fragile environment, and the absence of leverage to help people improve their lives or livelihoods.

An economy based on agriculture

Agriculture and cattle-raising activities, both focused on food production, are the main economic activities. The main crops are: quinoa, potato and other tubers, fodder and some leguminous species and vegetables. In general, yields are low because of the limited use of sown seeds, fertilizers and machinery. Drought, floods and frost events are also significant factors.

By the middle of the twentieth century both Bolivia and Peru had independently begun reform processes directed at modifying land ownership. In both countries, land was formerly concentrated among a few owners of large land holdings. But the reform effort resulted in a decrease of agricultural production and an excessive fragmentation of the rural property, particularly in Bolivia, where rural holdings, in extreme cases, are no more than a few square metres. In such conditions only small-scale subsistence agriculture is possible.

Other industries, including agro-industry and fishery, are also present within the system, but they are generally underdeveloped or inefficient.

Water Resources

Natural characteristics

Four main hydrographic basins form the TDPS system: Lake Titicaca, to the north of the system, is the main one. Its principal tributaries are located in Peruvian territory. Of these, the Ramis River is the most important as it represents 26 percent of the tributary basin.
The main aquifers are located in the middle and lower basins of the Ramis and Coata Rivers, in the lower basin of Ilave River and in a strip that extends from Lake Titicaca to Oruro, bordering the eastern ridge. The approximate total volume of groundwater that goes into the system is 4 m3/s. Most of this groundwater comes from tube wells used to supply water to cities. Such is the case of El Alto, Oruro and several other small towns.

There are higher levels of salinity found in the south of the TDPS system, a result of greater rainfall in the northern part of the system that reduces the concentrations of dis-solved salt. On the other hand, evaporation, which is greater in the southern part of the system, increases the concentration levels of dissolved salt. Maximum salinity values were found in Coipasa Salt Lake where evaporation is high and rainfall is only 200 mm per year.

Human impacts on water resources

Taking into account the fragility of the system with regard to flood protection and prevention, a series of  flow regulation works have been defined at basin level and in the system in general. In 2001 the first dam was finished, close to the International Bridge over the Desaguadero River. The main objective of the dam is to prevent, or at least protect, the surrounding area from floods. Other benefits of this dam include protection of the vast fish populations and aquatic vegetation and provision of an extended secure irrigation. Organic and bacteriological contamination is caused by human activity, in particular urban wastes and mining. Poor waste disposal is the central cause of organic contamination in all the important urban centres in the basin.

Endangered species 

High economic value non-native fish species such as trout and mackerel were introduced into Lake Titicaca around 1930. Since then some native species such as karachi (Orestia sp) and boga (Trichomicterus sp) have decreased, and their populations are considered vulnerable and endangered.

Over-harvesting 

Land areas suitable for crop and pasture are comparatively smaller than the occupied land with the percentage of areas exploited above their capacity reaching 35.2 percent. This overexploitation is one of the serious environmental problems affecting the high plateau, especially considering the area's very low productivity and the very rudimentary technology used to exploit it.

Data and information on water resources 

Since the creation of the Binational Autonomous Authority of Lake Titicaca (ALT) in 1993, several efforts have been made to consolidate the available information on water resources in the TDPS system. Most of the information was scattered among different institutions in Bolivia and Peru.
The creation of ALT and the elaboration of the Master Plan allowed data and information from different sources to be systematized and Bolivia and Peru now share this information through ALT.

Needs, uses and demands

Drinking water and sewage systems are largel y deficient throughout the TDPS area, as shown in the table below. Average drinking water coverage in major cities reaches about 60 percent. El Alto is the only city that has a wastewater treatment system. The other main cities in the TDPS (Oruro, Puno and Juliaca) do not have appropriate systems and their sewage disposals are a cause of water contamination.

About 48 percent of the TDPS system area is used for agriculture, distributed as shown in
the table below.


Agriculture use in the TDPS system

Crop production 4.4%
Grazing 21.7%
Grazing-forestry 14.9%
Other uses 7%


Most of the crop production area is located in the areas surrounding Lake Titicaca. However, only 17 percent of the total area is truly suitable for crop production. Therefore, soil erosion and degradation are a major concern.
Excessive property fragmentation is another common problem throughout the system. This fragmentation causes low crop productivity because farmers are not able to use technology to increase their crop yield. Energy consumption in the area is low and the principal source of energy is biomass (about 70 percent), those who have access to electricity are mainly urban dwellers.

Electricity coverage in the TDPS system

Peruvian side 21%

Bolivian side 29.8%


Management Challenges

The surface of Lake Titicaca is evenly distributed between Peru and Bolivia, countries that exercise an 'exclusive and indivisible joint ownership' over its waters. In fact the joint ownership model not only applies to the water of Lake Titicaca, but also to the watershed, as a way of ensuring integrated management of the water system.

Institutions 

Three institutions operate in the TDPS system area with clearly defined roles; these are:

• the Ministry of Sustainable Development and Planning, in Bolivia;
• the Peruvian Development Institute (Peru);

Two national projects were established for Peru and Bolivia and both technically depend on ALT. The Bolivian project is the Unidad Operativa Boliviana (Bolivian Operative Unit, UOB) located in La Paz, and the Peruvian project is called the Proyecto Especial del Lago Titicaca (Lake Titicaca Special Project, PELT), located in Puno. The units are responsible for coordinating actions with national governments and for centralizing information. The Hydrological Resources Unit and Master Plan Management Unit are in charge of monitoring the water resources and tracking development of the Master Plan, respectively. Figure 21.5 illustrates the structure of the ALT.


Development plans 

The Master Plan, developed with the cooperation of the European Community, was drawn up between 1991 and 1993 under the title Master Plan for Flood Prevention and the Usage of Water Resources of the TDPS System. This plan constitutes the basic reference and twenty-year framework for the future development of the system, and is based on the following elements:

• Focusing actions in a framework of sustainable use of natural resources, with resources as the central element;

• Recovering the system's ecological integrity in terms of protecting endangered species, replenishing fish populations and mitigating human impact on the system;

• Promoting human development within the basins.

Lake management shows a good degree of adjustment to the first two points. However, promotion of human development within the system has had a low level of success due to the difficulty of overcoming basic poverty in the area.



Useful links 

• Read the complete case study, published in the first edition of the UN World Water Development Report (WWDR1)
To know more about Lake Titicaca, here is a list of interesting projects and organizations:

• Brochure on the TDPS System published in 1992 by the Binational Autonomous Authority
.
• United Nations Development Programme/Global Environment Facility (GEF/UNDP) - Autoridad Binacional Autonoma (ALT): Joint project on biodiversity conservation in the TDPS system/ (in Spanish).

• Virtual information centre on water resources in the Altiplano, (in Spanish).ulty of overcoming basic poverty in the area.