In achieving its goal to replenish water equivalent to its 2015 sales volumes "back to nature and communities", Coca-Cola gave itself a compelling sustainability story to tell consumers. Greg Koch, senior director of global water stewardship at The Coca-Cola Co, spoke with Ben Cooper about what "replenishment" means, and why getting the minutiae of the methodology right is so important.

The concept behind Coca-Cola's water replenishment strategy is relatively simple, but the work behind it, the methodology supporting it and the lengths the company goes to ensuring its claims are recorded and communicated transparently and effectively are most certainly not. What Coca-Cola has sought to establish is a concept and goal that consumers can relate to easily with a methodology behind it that is unimpeachable and reflects the many nuances and complexities behind the water challenge.

Greg Koch, senior director of global water stewardship at Coca-Cola, says the company is "hyper-transparent about the methodologies and the calculations" it uses for every Replenish project. Coupled to the academic peer review process the strategy has undergone, Koch adds, "our partners are very notable – hundreds of local and global and regional NGOs, aid development agencies and other types of partners, so they're all part of this quantification work when we quantify a project".

Koch stresses that Replenishment itself is not Coca-Cola's water strategy, which incorporates other dimensions such as advocacy, awareness-raising and sanitation. Replenish represents a "subset" of Coca-Cola's water activities that can be quantified.

Greg Koch, Coca-Cola Co's global water stewardship director

Among the projects Koch highlights are the Paw Paw River Watershed Restoration, which is calculated to yield a quantity benefit of 231.50m litres per year; River Nar Land Management Improvements in the UK, yielding 188m litres annually; and the construction of Check Dams in Rajasthan, Himachal Pradesh and Uttar Pradesh, aimed at increasing groundwater recharge and improving supply reliability for agriculture in a region subject to severe droughts. These last projects are calculated to replenish some 3.6bn litres a year.

Demonstrating that the group puts back more water than it uses is clearly a powerful message to consumers about the company's commitment to water stewardship. "It is a signal of two things," says Koch. "Our commitment to water stewardship outside our direct operations, and the magnitude of the actions we have taken."

To make that quantifiable achievement tangible to consumers, it needs to relate directly to what the consumer experiences, Koch stresses. This actually makes the calculation Coca-Cola undertakes to make the claim that it has returned a volume equivalent to 115% of the water used in its beverages last year a little circuitous.

While Coca-Cola officially used 300.19bn litres of water in its operations in 2015 – 149.09bn litres in the production process and 151.1bn litres as ingredient – this is not the figure on which the company bases its 115% claim. Instead, Coca-Cola sets its total sales volume figure of around 166bn litres, which includes the 151.1bn litres of water that leaves its bottling plants in cans and bottles and the water added at point-of-sale through its fountain business notably in Europe and the US, against the estimated 191.9bn litres of water returned to nature and communities through Replenish projects, to reach the 115% figure.

The calculation may be convoluted but the intention, Koch explains, it is to make it tangible for the consumer.

"We did take the consumer's perspective," he says. "When they experience one of our products, it is in its finished form. They have a bottle or a can, or a drink they pour in a McDonald's and that's how they're experiencing it. That's why we tie our replenish percentage to our sales volume. What does the consumer see? 'I've got a product in my hand': Coke's doing projects that add up to it plus 15%."

Koch also points out that had it not included the water added through fountain sales, its positive replenishment percentage would have been even higher. "We want to hold ourselves to a higher standard," he says.

However, Koch concedes this achievement does not mean Coca-Cola is water-positive at every plant. "It doesn't signal a complete balance at every site," he concedes. "We're very clear that's not always the case."

Koch says the company's governance procedures should ensure that plants do not negatively impact local water supply. However, he stops short of saying these procedures provide a guarantee that would make a goal for water-scarce locations superfluous.

"I wouldn't use the word 'guarantee'", says Koch. "I don't like to use absolutes. There are some places where perhaps more data is needed to fully understand groundwater scenarios and we're working to do that. I also wouldn't say 'and therefore we don't need a site-specific goal in water-scarce areas'. It's something to consider, a sort of a belt-and-suspenders-type approach."

Koch also alludes to problems of public perception around plants in water-scarce areas where the plant is using a separate water source, but the community is experiencing scarcity and associates it with Coca-Cola. "Their perception becomes reality," he says. Avoiding localised problems, where the water supply to a plant conflicts with community access to water causing tension with communities and local governments, is a key aim of Coca-Cola's water strategy.

Having suffered from such issues and resulting reputational damage in the past, Koch believes Coca-Cola is in a very different position today. Interestingly, when asked if the group is in an immeasurably-different place than a decade ago, Koch replies: "We're in a measurably different place, absolutely." That, again, underlines the emphasis the company places on a transparent and quantifiable solution to what was once a severe reputational issue for the group, and the continuing challenges around water that lie ahead.

Coca-Cola's water strategy, Koch concludes, is designed to "allow us to protect manufacturing capacity and the ability to grow where sustainable from a water standpoint. I'd like to say that our programmes, the governance around them, and our actions, are doing that. Are there areas where the perception is still challenged? Yes."

While Coca-Cola has reached its 2020 target four years ahead of schedule, this does not leave the company open to the accusation of setting itself an unambitious goal. Coca-Cola might ask for testimony from the remaining 499 Fortune 500 companies in making a case that this wasn't easy.

It should also be pointed out that Coca-Cola is committed to achieving this positive replenishment figure against sales volumes every year, so the challenge is ongoing. Nevertheless, having achieved what it first publicly aspired to do in 2007 does leave Coca-Cola without its strong headline target on water.

Koch says the company is always prepared to listen to "insights from others" in relation to its water strategy and it may find the setting of a bold, new goal focused on water-scarce areas to be a popular suggestion.