As environment minister in the spring of 2012, I was warned that the chance of avoiding a massive drought was about 3%. The two preceding winters were so dry that levels in reservoirs and the aquifers were dangerously low. Anything approaching normal summer rainfall that year meant a huge economic, social and environmental nightmare. We had been planning for the impact of the drought for 18 months before this conversation but as the summer drew near I started to wonder how we were going to keep the taps flowing as the world looked to Britain for the biggest sporting event on the planet.

While the thought of the jubilee celebrations and the Olympic Games in a city whose parks were brown and where the trees were prematurely leafless was a worry, the real problem would be a third dry winter. If that had happened, we would by the spring of this year have been facing the spectacle of the sixth biggest economy in the world having standpipes in the street. Businesses would be closing because they could not get the most basic raw material they needed for production. But then it started to rain. Soon, my attention was diverted to flooding. As I trudged through the stinking misery of flooded homes and businesses, it was hard to imagine such extremes in such a short space of time – or that we had just dodged a bullet that was a 97% certainty.

It is staggering how short our memories are. The drought showed us that much of the south and east of England has at best a precarious water supply. A region that has one of the most dynamic economies in Europe risks being brought to its knees by a lack of the very substance most people here and abroad think we have in abundance.

So how do we get out of this hole before the next drought? It needs a bit of vision and that was not very apparent in parliament earlier this month when we debated water issues. The debate centred on the important matter of keeping bills down for hard-pressed households. What was missing was an understanding of the need for more investment in our water infrastructure. The debate focused on just the perfectly virtuous but short-term concerns of keeping bills low in the next few years and the daft call from some that renationalisation of the water industry was the answer.

One of the successes of privatisation has been the £116bn investment in water and sewage infrastructure. If we are going to have a water industry that is resilient to our changing climate, just talking down the water companies and talking tough about how we are going to constrain them in the future means the investors could shy away from the UK regulated sector. I am happy to attack dodgy corporate models that allow unethical tax avoidance, but I am not sure a very good case is being made by those who claim there is something totally wrong about our water industry.

Unlike some in the House of Commons, I am delighted when a sovereign wealth fund, an international private equity company or a global pension fund invests in our water sector. There are many other places and sectors around the world where they could go. We are only going to see new reservoirs, water mains or much-needed innovation if we take a long-term view on presenting the water industry as a safe place to invest. The key point is that investment is not only good for fund managers – it is good for the customer.

Around two-thirds of our rivers are failing ecosystems. Much of the cause for this shaming statistic is over-abstraction. We suck aquifers dry to provide cheaper water for an increasing population in the south and east of England. Most of the water we use comes from out of the ground or out of our rivers. But unsustainable abstraction ultimately costs the very households we want to protect. Dry aquifers mean greater cost down the line if the taps are going to continue to flow. We need a relentless drive to use less water through increased demand management. Southern Water's universal metering project should see a reduction of water use in most households by around 10%. Other water companies and policymakers should be watching this project closely.

So how do we avoid the standpipes in the street? How do we avoid the image being flashed around the world of the country that developed state-of-the-art water engineering being reduced to the shambles you might find in a sub-Saharan dictatorship? Well, luckily, the policy work has been done. In Defra, we produced a water white paper that was almost unique in terms of government policy. It was welcomed by green NGOs, the water industry, both sides of the political divide and the regulators. All that is now required is for it to be implemented. There is a water bill that will be debated in parliament in the coming weeks.

This will, among other measures, create new incentives for companies to enter the water sector with innovative new water and sewage solutions. It will see benefits for customers by greater competition.

But the bill is only part of the solution. For the sake of the water company customers of today and tomorrow, and the environment that supports them, we need meaningful abstraction reform, proper demand management and increased investment in reservoirs, pipes and other infrastructure. Politicians need to do something alien to their default position of looking at a five-year time scale. This is the time when we can and must invest for a long-term sustainable water sector.

Richard Benyon is Conservative MP for Newbury