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The progressive desertification of Goa

Nandkumar M Kamat

First Goa will be tormented by water supply crisis lasting till middle of June. And when the rains arrive there will be unprecedented stagnation of water and heavy flooding. For the next one month there will be very severe drinking water supply crisis mainly on account of a deficient monsoon, inadequate post monsoon rains, and negligible pre monsoon showers thus rapidly drying up the surface freshwater resources. But such conditions had existed in past so what has changed now? It is the less discussed progressive desertification which one notices all over the state. Even the state wildlife sanctuaries are so dry that it is difficult to believe that these areas falls under the Western Ghats ecosystem.

Drying conditions are ecological indicators of progressive desertification of Goa. Unsustainable urbanisation leaves its ecological footprints in surrounding areas. Such urbanisation causes ecological simplification by transforming natural landscapes, by removing local food chains, food webs, altering ecosystems, impacting biodiversity, and destroying habitats.

Google Earth satellite images of landscapes outside protected areas from 2002 prove how land use changes have been causing progressive desertification. The massive excavation undertaken by an active politician near the ancient Bhatim lake built in the 11th century by the Kadamba Dynasty in Sant Andre Constituency shows that no vegetated area in the state will escape fragmentation and consequent soil erosion. This watershed was not touched in two thousand years but has been now opened for quarrying soil and rubble.

Goa’s freshwater resources on paper total just 8530 million cubic meters. All the 11 rivers are drying fast as their watersheds have been ravaged. Usable freshwater resources are pegged at 1800 million cubic meters. There is no capacity addition to freshwater storages. Consumer water demand is increasing with urbanisation and industrialisation. Unlike western countries, there is no demand management during summer. At a very conservative level, washing a vehicle needs minimum 50 litres of water. Even if we consider that each owner washes the vehicle once in a week the water demand is 200 litres per month or 1600 litres per year excluding the monsoon. Multiply this by 15 lakh vehicles in the state. You would be amazed to know that only to wash vehicles, Goa is generating a demand of 2400 million litres per year or about seven million litres per day. This much water can be supplied to a population of about 50 thousand consumers daily.

Desertification signs are visible in dry hillsides covered by invasive weeds, eutrophicated waterbodies, dry beds of primary and secondary streams, dry rivulets and 41 small tributaries of major rivers with meagre flows. Desertification destroys capacitance to retain water so floods ravage such landscapes.

 Goa’s communidades or co-operative village associations prevented desertification and flooding by focusing on proper planning. They had no consultants. There were no technical drawings or printed maps. They fanned out and surveyed on foot the landscape contours in each micro watershed. They began planning drainage backwards from sea to interior, where estuaries have open mouths and extended it backwards from estuaries to rivers and till conjunction of tributaries. While laying down this drainage they reached sources of primary streams. They consulted people in nearest river basin. They used the river basin as the fundamental eco-topo-hydrographic drainage planning unit. They used micro watershed topography for designing the local monsoon drainage. They allowed water flow by gravity and no hydraulic pumps were used. Drains were laid to permit smooth streamline flow. Monsoon water holding, balancing reservoirs were excavated in all paddy fields.

In Khazan areas, the sluice gates were placed strategically. The height of riverside bundh which were six metres wide was kept at six metres uniformly. They ensured that monsoon stormwater flow from all micro watersheds would pass over soft soil for slow percolation and aquifer recharge and they also maintained wild shrubs and hydrophytes for removal of sediment. During summer they desilted all drains and used the silt to strengthen the nearest bundhs. They piled up and lined all backwaters with laterite rubble to reduce erosion. They allotted and fixed responsibilities of hydrological inspectors like Vigio, Kamots, Painis. They ensured voluntary cooperative labour so all stakeholders could rush to repair the drainage system. They raised community subscription to build culverts with Roman arches in laterite and mortar. This system prevented desertification and flooding. People could survive the worst of the droughts. Floods were very rare and confined.

After liberation of Goa the ill-informed engineers followed the British India type drainage systems. The foreign consultants finished giving the final touches to destruction of traditional eco-engineering, geo-engineering and hydro-engineering knowledge. Urbanisation needed sacrifice of land resources so no attention was paid to its impact on traditional drainage, water conservation, and anti-flooding structures meticulously designed and seamlessly integrated in the landscape mosaics by the local communities. Dismantling of the traditional anti desertification and anti flooding systems during past 60 years is the major reason for the water supply crisis during summer.

Destruction of natural capacitance of the local ecosystems by encroachments on floodplains and reclamation of low lying areas has now made Goa extremely vulnerable to man-made flooding. Henceforth it will be a vicious cycle -progressive desertification followed by seasonal flooding. Seasonal flooding further erodes the ravaged landscape thus accelerating desertification. The solution needs fundamental policy reforms, legislative and administrative reforms aimed at integrating traditional knowledge with appropriate modern technology. That needs sensible, sensitive and sensitised environmental governance. Where can one find it?

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