Formed in 1969 and only one perennial river: Malappuram, the district now under the heaviest rain warning

Background

Malappuram, one of the districts carrying the heaviest rain warning this weekend, was formed on the 16th of June 1969.
The district covers 3550 sq. kms, which is 9.13% of the state's total area and ranks 3rd in the state.
Four rivers flow through it — the Chaliyar, the Kadalundippuzha, the Bharathapuzha and the Tirurpuzha — and only the Chaliyar is perennial.
It is bounded by the Nilgiris of Tamil Nadu on the east, the Arabian Sea on the west, Kozhikode and Wayanad on the north, and Palakkad and Thrissur on the south.
The Nilambur and Wandoor blocks lie in its eastern, hilly part.