What conserves more water: Your five-minute shower or fixing a leak?

What do Americans have to say about water consumption?

A new Associated Press-GfK poll finds most Americans think of water as a limited resource that can be depleted if people use too much. In case of drought, seven in ten Americans think the government should place limits on the amount of water people and businesses can use. A majority of both Republicans and Democrats believe that water is a limited resource.

And it seems that the US is getting the memo. According to data collected by the US Geological Survey, water use in the United States in 2010 was estimated to be 355 billion gallons per day. This was 13 percent less than in 2005 and a significant change from the average 400 million gallons per day reported form 1985 to 2005.

While overall consumption is down, public perception still lags. A survey conducted by Dr. Shahzeen Attari last year found that most participants wrongly thought curtailment was the most effective strategy they could implement to conserve water in their lives (taking shorter showers, turning off the water while brushing your teeth, etc.) as opposed to efficiency improvements (replacing toilets, retrofitting washers etc.).

“People may be focusing on curtailment or cutting back rather than efficiency improvements because of the upfront costs involved,” Dr. Attari said in a news release. “It is also surprising how few participants mentioned retrofitting their toilets. Even though toilets use less water volumetrically than washers and showers per use, the frequency of use results in the highest water use overall.”

Attari also said, “Given that we will need to adapt to more uncertain fresh water supplies, a problem that the state of California is currently grappling with, we need to find ways to correct misperceptions to help people adapt to temporary or long-term decreases in freshwater supply.”

The Lower Colorado River Authority gives several tips for saving water in the bathroom.

• Check regularly for any leaks in your toilet, faucets, and water hose and fix them (water saved: up to 200 gallons per day).
• Install a low-flow shower head (water saved: about two gallons per minute)
• Replace older, large-use toilets with the newer high-efficiency toilets (water saved: half a gallon to five gallons a flush)
• Take short showers and save the bath for special occasions (water saved: two to five gallons per minute).

National Public Radio interviewed engineer Shankar Vedantam on Attari’s findings. When asked about the expense of a high-efficiency toilet, he pointed out that it would likely save you money in the long run.

“The hidden bias here…is we pay a lot of attention to the cost of something like a new toilet, which is a one-time expense. We are far more likely to live with an inefficient appliance, where the expense mounts over time. Now, of course, the point is if my toilet is inefficient and my other appliances are inefficient, eventually the wasted water is going to end up costing me more than just going out and buying a new toilet.”