Vaitarna is a little river which arises in the Sahyadris and drains into the sea just north of Mumbai. It has been called India’s most polluted river, at least in the lower stretches. The upper parts have been called the most dammed river in India. This stretch is clean enough to supply drinking water to tens of millions. The 154 kilometer long river has three dams, which, between them, hold nearly a billion cubic meters of water. Why so many dams, I wondered as we walked along the uppermost of these dams.
The answer lies in the weather and the land. The Indian Ocean monsoon dumps incredible amounts of water on this land for three months every year. It has done that for tens of million years. The land itself was formed in the volcanic eruptions sixty to seventy million years ago, during the time that the dinosaurs died. The ancient lava flow cooled into the basalt of the Deccan Traps. Later it was weathered in the hot house that the earth became thirty million years ago. The weathering formed the thin red laterite soil that covers the Sahyadris. The deep channels eroded into the volcanic basalt channels the seasonal waters as they flow into the sea. The dams catch and store the rains.
This beautiful landscape is the shadow of incredible volcanic eruptions. The soil is thin, because the rain washes it away. Where it collects in deep trenches, agriculture is possible. Around the dams rich agriculture has developed in the last hundred years. You look at this land and see few trees. The highest growths are usually tall shrubs. The thin soil of the highlands is covered by low herbs, creepers, and grasses. Weird new species have evolved in the thin metallic soil. It is an amazing place for wildflowers and strange animals. The harsh land has given refuge to some hardy exotics.
Among them you may count the water spinach (Ipomoea aquatica). Although the locals do not seem to know it, it is edible. In this it is like many other morning glories in the genus Ipomoea. I’ve eaten its leaves both steamed and stir fried in my travels across Asia. It is hardy, grows in poor soil, and is a sure indicator of the presence of water. It needs little effort to cultivate. You just have to harvest it and eat it. I see it being used as a hardy decorative around the country. Why doesn’t anyone here eat it? Perhaps just the lack of knowledge about how edible it is.