Residential Customer Water Budgets

• IRWD’s rate structure takes into consideration both indoor and outdoor water use.  
   
• Water budgets are based on the number of residents in the home, the type of home (detached home, attached home or apartment), landscape square footage and actual daily weather and associated evapotranspiration (ET) data.
   
• ET is the amount of water that is lost by plants through evaporation and transpiration, and which needs to be replaced for the plants to remain healthy.
   
• Grass is typically the highest water-using plant in a landscape. Trees and shrubs use far less water than grass – but IRWD’s budget based system will assume that almost your entire landscape is covered with grass.
   
• Your budget should provide more than enough water to meet the demands of your landscaping.
   
• The base budget formula assumes the following:

Detached home (i.e. single family home): 4 people with 1300 square feet of landscaping

Attached home (i.e. condominium or townhouse): 3 people with 435 square feet of landscaping

Apartment: 2 people with no landscaping 

• Variances are available to make adjustments to the allocation for more people living in the home, medical needs, livestock, additional landscape or other special circumstances. IRWD has used parcel and other data to automatically calculate landscape variances for Santiago area customers.