The khazans are saline floodplains along Goa’s tidal estuaries, covering an area of 17,500 ha, which have been reclaimed over centuries by constructing an intricate system of bunds (dykes) and sluice gates. The dyke system consists of extrinsic (external) embankments made up of combination of Laterite stones and mud in order to minimize the erosive effect at such point. Intrinsic (Inner) embankments are made up of mud, straw and poles and are further divided into girdle type, undulating and wide bunds interconnecting smaller bunds.

The tidal inflow and outflow (flushing) of waters in these unique agro ecosystems is maintained by sluice gates made up of wooden doors. These sluice gates are strategically located along the contours and relief, elevated at the point of smooth inflow and outflow of saline water. These sluice gates primarily protect the adjoining fields from inundation and control the water flow in and out of the rivulets in most of the khazan lands. The sluice gates help to flush out during the monsoon that enables to harvest the Kharif crop during monsoon in certain areas.

Khazan lands are ecologically, economically and socially very important for both agriculture and pisciculture. The local farming community traditionally practices rice cultivation by growing salt–tolerant species during monsoon in conjunction with shrimp aquaculture during off seasons. These lands serve as emergency storm water receptacles and thus play a major role in preventing floods. The mangrove vegetation near the external or internal bunds provides the most important natural anti-erosive barrier.

Inundation

Khazan lands gets inundated mainly due to breaching of bunds, caused of barge activities as well as purposeful breaching by local people for pisciculture. These have resulted in flooding of such areas leading to various adverse effects:

• Loss of Agricultural crops
• Destruction of Saltpans
• Destruction of coconut grooves
• Increase in soil salinity, thereby affecting its fertility
• Saline water intrusion in groundwater resources
• Air corrosion

Willful and other illegal inundation, poor management, uncontrolled and unplanned urbanization, pollution and Siltation, Konkan Railway intrusion and lack of political will are major factors responsible for degradation of Khazan lands.