Water management in semi-arid areas.

Evaluation of subsurface dams for rainwater harvesting in NE Brazil.

 

For water storage in the dry zone of the northeast of Brazil, subsurface dams have proven to be an effective and low cost solution and further investigations should be made to optimize the construction and operation. The target of this research is the assessment of planning, the construction and management of subsurface embankment dams, particularly under consideration of hydrology and ecology of intermittent rivers, geology and geohydraulic, water quality, rural development, and socio-economic aspects.

 

The storage of water in riverbeds by subsurface dams will lead to a significant retention of water. The available water amount is controlled by the dam management. The stored water is harmless for human use; however, the salinity is increased. In operated subsurface storage fluctuations of the salinity occur, but during unused storage a steady increase is observed. Microbiological investigations show a higher amount of coliform bacteria, however, it is lower than at surface storage basins. The development of a water protection zone around the subsurface basin appears necessary to avoid pollution with fecal germ.     

River Mutuca, NE Brazil, with subsurface dam for rain water harvesting. The sub-surface dam reaches to 8.5 m depth
River Mutuca, NE Brazil, with subsurface dam for rain water harvesting. The sub-surface dam reaches to 8.5 m depth
Irrigation and agriculture in the dry riverbed of Mutuca River
Irrigation and agriculture in the dry riverbed of Mutuca River

References: 

  • Carvalho, R. M. C, Sobral, M., Costa, M. R., Gunkel, G., Silva, M. M. & Lôbo, L. (2009) Subsurface Dams for Water Storage and Sustainable Development in Semi-arid Areas. In: L. M. G. Duarte & P. Pinto (eds.) Sustainable development: energy, environment and natural disasters. Fundação Luis de Molina, Lisboa. 149-158. 
  • Regueira da Costa, M., Cirilio, J. A., Gunkel, G. & Gico Lima Montenergro, S. M. (2005) Qualidade da água em fontes superficiais e subterrraneas no semi-árido brasileiro. In: 7º Simpósio de Hidráulica e Recursos Hídricos dos Países de Expressão Portuguesa, 2005, Évora. Lisboa : APRH, 2005.14 pp.
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