Water for people.pdf - WHO Thailand Digital Repository

4 7 4 / P I L O T C A S E S T U D I E S : A F O C U S O N R E A L - W O R L D E X A M P L E SLake Titicaca Basin, Bolivia and PeruWater for ecosystemsThe TDPS has a broad variety of flora and fauna. Biodiversity in thebasin area is in a precarious position due to the overexploitation of somespecies. Both the Bolivian and Peruvian governments have responded byestablishing protected areas to help preserve these living resources.Aquatic floraGreen algae and diatoms are the main components of Lake Titicacaplankton, but there are also cyanobacteria with the capacity to fixnitrogen, as well as large populations of chlorophyll andclorococales. Algae populations are found down to depths of 80 and100 metres, while nitrogen from agricultural runoff seems to be themain constraint on algal development.Macroscopic plants – macrophytes – are represented in thesystem by about fifteen species and are located in shallow zones.Some macrophytes such as Totora and Llachu are importantelements for animal feed, especially for cattle. They also helpabsorb heavy metals such as arsenic, zinc and lead. In the sameway, Totora is of central importance for many human activities suchas building boats and thatching roofs.A new algae called Carophiceas (Charas) has been observed indeeper sectors and is important for biomass in the lake systems, asit appears to have a good resistance to high levels of salinity.Aquatic faunaZooplankton, benthic fauna, fish and frogs make up the principalaquatic organisms living in the TDPS system. Among the maingroups that form the zooplankton, copepods are broadly dominantover the clodoceros population, and their reproduction occursthroughout the year. Globally, more than 95 percent of the benthicpopulation in Lake Titicaca is found within the first 15 metres of theMinor Lake and in the first 25 metres of the Major Lake.The TDPS system is rich in fish species, distributed in differenthydrological units of the system. Lakes Titicaca and Poopó have themajor concentration of commercial fish species.The frog population is grouped into four genera, among themthe Telmatobius genus, which includes one of the biggest aquaticspecies in the world.Terrestrial plants and animalsPlants and animals living in the TDPS system have adapted to theecological conditions of the region. The system can be divided intotwo main regions: Puna (lower than 4,400 m.a.s.l.) and theAltoandina (higher than 4,400 m.a.s.l.). There are different speciesof bushes and trees in each, including grasslands and native trees.In addition, Lake Titicaca itself was declared a Ramsar site in 1998.It is the only Ramsar site in the TDPS System (see box 6.5 inchapter 6 for further details).Water and citiesAccess to sanitation is low, at only 17.2 percent throughout thebasin. One city, El Alto, has a drinking water system administered bya private company (Aguas del Illimani). The others cities aremanaged by the municipalities. Average coverage in major citiesreaches about 60 percent. Average tariffs for drinking waterconsumption vary from US$0.13 per litre in Puno and Juliaca toUS$0.22 per litre in El Alto. The smaller urban centres have smalldrinking water systems that are managed by the community.El Alto is the only city that has a wastewater treatment system.The other main cities in the TDPS (Oruro, Puno and Juliaca) do nothave appropriate systems and their sewage disposals are a cause ofwater contamination.Water and industryWater demand for mining and industrial activities is not a majorproblem inside the TDPS system because there are few industriesand their water consumption is very low. Water use for mining hasnot been measured, but is considered insignificant. Conversely,mining is an important source of water contamination.Industrial pollution of waterways results from inappropriatedischarge of wastewater and drainage from mines and mineralprocessing systems. Water from mines is very acidic and highlycontaminated with heavy metals, particularly in Oruro wherematerials have appreciable amounts of pyrite that producessulphuric acid when it comes in contact with water. This acidleaches metals such as arsenic, cadmium, cobalt and nickel,producing contaminated water that eventually flows into the basin.Water and energyEnergy production is not a major activity in the TDPS system. Althoughthere is a lack of information with regards to energy, it has beenobserved that energy consumption in the area is low and the principalsource of energy is biomass (about 70 percent). Only 21 percent ofhomes on the Peruvian side and 29.8 percent in Bolivia, mainly inurban areas, have electricity. This electricity is generated outside thesystem and water is not used for hydraulic energy production. There isa small-scale use of liquefied petroleum gas, limited to urban areasdue to the difficulties inherent in its transportation.Other usesAlthough recreation and transportation are not considered activitiesthat can affect the water balance or water quality, they aresignificant activities when viewed as potential new alternatives fordeveloping the TDPS area.Transportation is of fundamental importance in Lake Titicaca.The lake includes twelve islands where the local population rely onboats and ships for travel. Likewise, Copacabana City, located in the