Context: Recently,  Salim Ali Bird Sanctuary, the low-lying floodplains of Goa host an estuarine agricultural system called Khazan farming.
About Khazan Farming

• A Khazan is a marvel of tribal engineering. It probably originated among the prehistoric Gauda Tribes of Goa.
• They had a fantastic working knowledge of the rhythm of the monsoons and the flow of water during the tides.
• They also knew how to build bunds, dikes, canals, and sluice gates to control the flow of this water. As a result of this primitive but highly effective technology, they were able to reclaim vast tracts of mangrove forests, and other coastal lands and put that land to other uses. Growing paddy, cultivating prawns, and panning salt, were the three main uses for the Khazan lands.
• Their knowledge of the flow of water and their ability to control that flow was truly impressive. Especially when you keep in mind that they created such systems almost 3500 years ago. With simple primitive technology.
• They usually picked an agriculture field near the waterfront, along with an inner small embankment. To this area, they built protective dikes ( the inner dikes are called mero, the thick outer dikes are called bunds) and sluice gates, which were opened and closed at specific times to control the flow of water
• There is also a shallow pit called a ‘poiem’ and a water channel to circulate water into the fields. Most of these were made by hand with rudimentary materials such as mud, clay, and straw.

How does it work?

• Centuries ago, people in this region reclaimed low-lying brackish coastal floodplains and mangrove forests.
• They constructed bunds using locally available material to prevent the ingress of saltwater, which killed the halophilic mangroves.
• To control the flow of tidal waters, they built openings in bunds fitted with one-way gates.
• These channels would fill in with the oncoming tide and bring with them fish, crab and shrimp, and the gates would automatically shut when the water level was equal on both sides.
• This prevented the water from overflowing into the fields used to grow paddy and which has a low tolerance to salt.
• When the tide receded, these gates would open outwards automatically, allowing the water to drain out.
• During this time, a bag net was set at the gate to catch fish that had entered in earlier.

Benefits of Khazan

• Every bit of space was precious and used efficiently — the bunds were used to grow a variety of vegetables.
• The Khazan system allowed for the farmer and the fisher to harmoniously coexist and was the key to sustaining what is considered Goa’s staple — fish, curry and rice.