Raymond Joseph is a journalist who lives in Cape Town, South Africa. The opinions expressed in this commentary are solely his. View more opinion articles on CNN.

My heart goes out to you as I read how your city, the sixth biggest in India, is rapidly running out of water

It brings back all-too-recent memories of Day Zero when Cape Town, South Africa , almost became the first major city in modern times to run out of water.

The crisis made headlines around the world for all the wrong reasons and exacted a high price in reduced tourism , a major source of income and employment . Tens of thousands of jobs in the agricultural areas around Cape Town were lost , while the area's famous wine industry was also hit hard

But last winter we had enough rain finally to break the back of the crippling drought. It has meant that we are entering a new rainy season with dam levels considerably higher than they were this time last year.

As I write this letter to share some of the lessons we learned, there are warnings on the radio of heavy rainfall and the possibility of localized flooding in some parts of the city over the next few days. Previously, with the prospect of rain over the weekend, you would have heard people moaning and groaning. But today, with the benefit of the hard-earned lessons we learned as we stared down the barrel of a loaded gun, most residents of Cape Town -- admittedly not those living in flood-prone, low-lying informal settlements -- are smiling at the prospect of a wet weekend.

Living with water scarcity and periodic usage restrictions is not new for us in South Africa. It is a reality on the southern tip of Africa, with forecasts of growing water demand from agricultural, industrial and municipal sources, according to recent research

But the prospect of a Day Zero felt foreign, even to us. For many of us, it was a life- and attitude-changing experience. Today, almost a year to the day after Day Zero was called off, saving water has become the new normal for many Cape Town residents.

Like so many other households, my family still takes two-minute showers or inch-deep baths. Afterward, the water is scooped into buckets and used to flush toilets and water plants.

It is also no longer a reflex habit to flush the toilet after urinating, even when using a public toilet -- something that outsiders who have not experienced what we went through find difficult to come to terms with.

Taps remain switched off in many public buildings and privately owned offices and shopping centers, where waterless urinals, hand sanitizer and signs reminding people to save water are commonplace.

An example of how much water is needlessly wasted was illustrated in a study by a young University of Cape Town researcher, who found that enough potable water to fill eight Olympic-size pools was flushed away in urinals on the campus each year. I would imagine that similar waste also happens in Chennai.

But there was also an upside to Day Zero: It sparked innovation and a huge growth in companies offering water-saving products, such as waterless toilet and urinal solutions. Companies supplying water from areas unaffected by the drought as well as others offering borehole-sinking services and suppliers of pumps also saw a boom in business.

India is a resourceful and tech-savvy country, and cities such as Chennai that are gripped by drought and water shortages should see this crisis as an opportunity to innovate and develop new products.

And while it is important to live in the here and now to ensure you have water for your daily needs, it is just as essential to work on future-proofing your homes and your city for a time when you will have to make do with less water on a more regular basis.

In Cape Town, harvesting rainwater makes sense, and many homes now have storage tanks connected to roof gutters to collect runoff water. There was a boom in companies that manufacture these tanks, along with companies that install them, which created new jobs.

Many other new water-related businesses and startups popped up, including companies that specialize in designing and installing greywater systems to harvest valuable secondhand water that would otherwise have gone down the drain.

So, be open to possible business opportunities the current drought might present and capitalize on them.

If you're fortunate enough to have a garden, get rid of the exotic plants and shrubs and replace them with indigenous varieties that are better adapted to local conditions and need less water.

Install water-saving shower heads, fix leaking taps and toilets, and change washers regularly. Most importantly, hold your politicians to account: They are partially to blame for the crisis you are facing, which is the result of poor planning and a failure to budget properly for water security.

Reward those who commit to ensuring that Chennai becomes more water secure and punish those who fail to deliver. In Cape Town, a perceived failure on water became an issue in South Africa's recent general election

And, as hard as it is to do at the height of your water crisis, remember that all things pass: The drought that brought Cape Town to the brink has ended -- for now.

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Cape Town learned from bitter experience, and we are now using less water than we are allowed to.

I hope you, too, will learn from the hardships you are experiencing and come out of it stronger and more water-resilient than before.

Yours in water solidarity,

Raymond