The Day Zero warning in 1972 that fell on deaf ears.

The front cover of Joe Lison's manuscript detailing Cape Town's water supply.

When the most recent drought to hit Cape Town threatened to leave many of the city’s residents without running water late last year, Dr. Solly Lison went in search of the manuscript his late brother Joe had completed writing in 1972.

In it he knew he would find details to prove that the city’s water crisis was decades old and that the disastrous events unfolding in the city were avoidable.

Dr Lison paging through his brother’s manuscript.

The manuscript, titled “From Rivulets to Reservoirs”, included research dating as far back as the 1500’s and predictions for the future, but it was said to be of no public interest at the time and went unpublished. Joe then donated a copy to the city engineer.

In it he had recorded an event in 1917, which closely resembled the threat of Day Zero the city faced last year, almost a century later.

It was predicted that by the end of March 1917 the water supply in Cape Town would be exhausted. However, it was also predicted that sufficient rain would fall the following month.

Restrictions and limitations were set in order to stretch the supply just enough to last the city until April. Supply to household taps were cut from 4pm to 6am the next day and citizens had to restrict their fresh water use to watering gardens, cooking and bathing.

Similarly it was announced last year that household taps were expected to run dry by the end of March 2018. Citizens were urged to use a maximum of 50 litres per day in an attempt to push back or avoid “Day Zero”.

In an attempt to save water the Cape Town Central Library removed handles off their bathroom taps.

But last month Cape Town welcomed the first hope-inducing rainfall of the season.

An analysis by the scientists of the University of Cape Town’s Climate System Analysis Group, Peter Johnston and Piotr Wolski, forecasted above average rainfall in April, below average in May and normal rainfall in June.

Despite this dams are only expected to reach a desirable level in about three years. Until then citizens will have to be water-conscious and efficient.

Follow the “From Rivulets to Reservoirs” series weekly to find out more as we unpack Joe’s manuscript as well as his fascinating life.