It's not rocket science: Cut your water usage and your bill will go down. But what if you could get money back on top of it?

That's what startup MeterHero is offering.

As a consumer, all you have to do is grant the company access to your online bills (for water, electricity and gas). The company looks at your last two years of usage and creates a baseline. And then every month that you use less than that amount, you get money back.

The cash rebates come from a monthly sponsor. In August, MeterHero is partnering with Rachio, a smart sprinkler system.

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"It works out well for the company to get in front of the people who are actively trying to save water and energy," founder and CEO McGee Young said. Previous partners include SolarCity, Heavenly Greens (which installs synthetic lawns) and the Florida Clean Water Network.

At just $1 per 100 gallons, you're probably not looking at a windfall. But Young said rebates average about $10 a month.

"We sent one for $160 to a customer in LA who decided they didn't need their green grass anymore," he said. "And then some people get like $0.38."

MeterHero launched in November, and its footprint is admittedly small. There are about 2,500 customers around the country, one-third of which are in California.

In July, MeterHero paid out rebates of more than $7,100, as its customers saved more than 331,000 gallons of water, 32,000 kWh of electricity and 2,400 terms of gas. Young expects even bigger numbers in August.

It currently takes a small cut from the rebates, but is also exploring several premium options. One is to work with landlords in multi-family buildings. Since one meter is used for all the units (and the landlord pays the tab), there's less of an incentive for residents to reduce usage. MeterHero has a few pilot programs that allow the residents -- and the landlord -- to split the rebate.

MeterHero is also working directly with companies on employee engagement programs. In several beta programs, employees are competing against each other to cut their usage at home. Not only does it make the company more environmentally-friendly, but McGee said it also inspires employees to conserve in the office -- they take a second look at lights that are left on overnight or water that's running.

The cash rebates drive consumers to be creative in a way Young never expected. Some MeterHero customers have written in to say they've started using felt balls in the dryer; others say they are flushing less.

"I see it as a gateway drug," Young said. "People will make a little change -- like taking shorter showers -- and get paid a little bit. And the next thing you know they're ripping out their lawn and replacing their toilets."