Rarotonga’s wetlands – taro swamps

Back on the subject of Cook Islands wetlands (see also the Ngatangiia Salt Marshes) the northern group islands don’t have any but most of the southern group have freshwater marshes and swamps while Mangaia, Atiu and Mitiaro have freshwater lakes albeit shallow ones.
Freshwater swamps on Rarotonga are, or used to be, on coastal plains and in flat-bottomed river valleys but many of them have now been turned into taro plots.
As you drive around the island you pass plots in various stages of production from overgrown and weed-infested, through freshly turned, with new shoots planted, mulched with kikau, black plastic or cardboard – often flattened beer cartons to healthy looking crops of rukau (taro leaves).
The plots are small but taro production is hard work. Everything is done by hand. Apparently once you’ve planted the taro in the lowlands, on raised beds with irrigation ditches, you can more or less leave them to get on with it – the plants grown in ponds take a lot more effort so I’ve heard.
Most if not all of the marsh wetlands on Raro have been used for taro or drained, filled and built upon. I don’t know of any in the original state.
Maybe on the outer islands some of the lakes have fared better or at least may be reverting to their original state now that so many people have left.
The area of terraces in the Tupapa valley (on the way to Te Kou) is really very impressive.

From A Directory of Wetlands in Oceania - Anna Tiraa

A series of terraced taro swamps extending for approximately 2.5 km along either side of the Tupapa stream from near its headwaters to the edge of the coastal plain. Water is channelled from the stream by way of a trench to the top of the top terrace, then down through the lower terraces to rejoin the main stream at the bottom. Traditionally, small stones were used to line the trenches to prevent erosion; in recent years, some trenches have been replaced with plastic and concrete piping. The taro plots generally follow the contours of the land and are laid out according to the patterns of customary ownership.
The terraced swamps were constructed for the cultivation of taro (Colocasia esculenta), and continue to be used for this purpose.
Although there is no legal protection, the taro swamps have been protected by their customary land owners for centuries.
The Tupapa valley has a timelessness and serenity as yet scarcely affected by the modern progress and development which has occurred elsewhere on Rarotonga. The terraces are of particular interest because of the pre-contact skill that went into their construction and the minimal change that has occurred in the overall design of the terraces down through the ages.