Calculating Water Savings

We all like to know how to how much water and money we are saving. At Hydrawise its no different and water saving is an important part of a Hydrawise unit’s job.

On your Hydrawise Dashboard you'll see a water saving figure. It is a percentage of the estimated water you've saved with your Hydrawise unit over the last week. We use percentages because we don't know the quantity of water you've actually put on your garden - but we do know how long you'd normally water your garden based on your settings so we show a water saving as a percentage of irrigation time.

How is this calculated?

We calculate water savings in 2 different ways based on the type of watering each zone is configured to do.

Smart Watering

When you first configure your Hydrawise system you'll enter your controller's location. Hydrawise has access to hundreds of thousands of weather stations worldwide so we are able to determine the average temperatures and rainfall close to your location. Traditional smart watering (ET-based) controllers take the last 30 years rainfall based on your zip code and use this and the accuracy can be poor. At Hydrawise, we know the weather is changing much more rapidly so we will take the average maximum and minimum monthly temperatures and monthly rainfall from your closest weather station and average this out over the previous 3 years.

From your local weather data we will determine the right amount of water to apply to keep your plants alive over the hottest part of the year - this is used as a baseline for your watering schedules. This is what your irrigation guy would have done when setting up a non-smart controller. The amount that you actually water is divided by the baseline to determine your water saving.

Our smart watering calculations are based on grass as the plant type. If you have drought tolerant plants then the watering requirements would be less and your saving reduced. Alternatively if you have plants which require relative high amounts of water then your saving could be increased.

Predictive Watering™

Zones configured for Time Based watering benefit from our Predictive Watering™ algorithms to also save water. Your water saving is calculated based on the actual amount of watering that the zone does (which may be increased or decreased based on temperature, rainfall or wind speed) compared to the amount you would have watered without the Predictive Watering™ adjustments.

So how much water will I save?

Well, this is difficult to know until we've been through a full year of watering.

For Smart Watering based zones we can estimate this based on the monthly average temperatures and rainfall we download from your closest weather station (this is the figure that we use in the Welcome email we send to you).

For Time Based watering your saving will be determined based on the thresholds that you set for the controller to stop, reduce or increase watering.