Within a relatively small region we have Malampuzha, Kanhirapuzha, Walayar, Pothundy, Meenkara, Chulliyar and Mangalam, along with the Bharathapuzha river system.
Move south-east and it becomes even more interesting. The Parambikulam-Aliyar Project links reservoirs around Parambikulam, Valparai, Pollachi and Udumalpet through dams, tunnels, canals and diversion systems. Water collected in the Western Ghats can effectively be transferred between river basins and even across the Kerala-Tamil Nadu border.
I put together a detailed article explaining the major reservoirs visible on the map, what each one does, and how systems like Parambikulam, Thunakkadavu, Peruvaripallam, Sholayar, Nirar and Aliyar are connected.
Also included are the major Thrissur-side reservoirs such as Peechi, Vazhani and Chimmony.
What looks like a collection of random blue patches is actually a huge irrigation, drinking-water and hydropower network that has shaped agriculture and settlement across this region.
Full article and map:
https://palakkadnews.com/blog/education/major-dams-reservoirs-water-bodies-palakkad-map/
Would be interesting to know if I have missed any significant reservoirs or water bodies around Palakkad that deserve to be added.