California is suffering from one of the worst droughts ever recorded: three years of low rain and snowfall have left the state in crisis, with the Sierra Nevada snowpack being the lowest it's been for 500 years. According to government data, 2014 was the third driest year in California over the last 119 years; it was also the warmest year on record.

That means California needs to find some innovative water conservation ideas, and fast. Authorities are trying to reduce evaporation and use seawater to tackle the drought, and the most recent proposal to be put forward uses one of nature's oldest and most recognisable water hoarders: the humble cactus.

Called Grassroots Cactivism, the idea is the winner of an Archinect's competition looking for solutions to California's drought problem. It won in the speculative category, so don't expect it to become a reality in the very near future, but it involves using the nopales cactus (also known as the prickly pear) as food for livestock and as a water cleaning agent.

With 80 percent of the state's water usage taken up by agricultural production, any savings that farmers make can have a significant impact on the overall drain of water supplies. Part of the cactus crop can be distributed to supermarkets and restaurants; part can be used as a cheap and effective water sanitation agent; and the rest can be used as animal fodder. It's a multi-use crop that can grow with very little water.

"At our cactus farm we propose to use this low-tech solution to improve and revolutionise existing wastewater management systems, as well as mitigate water usage in farming by supplying a crop that requires little to no water," writes architect and graphic designer Ali Chen, who came up with the idea. "As a hardy plant that grows locally, this cactus farm can be located anywhere in California. However, it is ideal to locate it near an existing reservoir for convenient releasing of purified water."

The effect this type of cactus can have is something we've known about for a long time - many Mexicans habitually dump cactus cooking water into polluted rivers and streams to help clean them up, while the pulpy flesh has previously been used to tackle oil spills. As Gizmodo reports, the idea isn't that far-fetched, and several other groups are promoting the use of cacti as climate change continues to affect our world.

As for Grassroots Cactivism, it's only a concept idea for now - let's hope the right people take notice of it and can help to put the project's wheels in motion.