Operation of Wastewater Treatment Works

I am monitoring a 2ml of treatment works for a population of 19,500. New growth is still continuing. At peak hours flow increases 3 times the design capacity and treatment works operate with two process controllers. At night no process controller is on-site and when is raining the WWTWs is overflowing, whereby screening is full of waste. Due to budget constraints we can not appoint extra process controllers. In my case i have got some suggestion, and i need some advice too: I suggest to add a buffer/balancing tank, whereby flow it can overflow in it when is raining or absent of process controller. Add some bypass line to Primary settling tank, to avoid overflow in the inlet. Your feedback much appreciated!