Understanding Water Budget Based Rates

Understand how MNWD’s water budget based rates are designed to allow for efficient water use based on your personalized needs.


Residential Water Budgets

Residential water budgets are calculated based on each customer’s landscaped area of their parcel, real-time localized weather data, and the number of residents in each home. These can vary month-to-month based on weather and number of billing days in each cycle. See below for how we calculate both our indoor and outdoor water budgets for our residential customers.


Indoor Water Budgets

Indoor water budgets for residential locations are calculated using three factors:

1) 60 gallons of water used per person per day

2) the number of people in the household

3) the number of days in the billing cycle

Each single-family home receives a default number of four people per home. Condominiums receive a default of three people per home, and apartments have a default of two people. Please contact us if you have more than the default number of residents in your home as you may require a larger indoor water budget.

Outdoor Water Budgets

Outdoor water budgets for residential locations are calculated using three factors:

1) irrigable area per parcel, including pools and spas

2) daily evapotranspiration

3) plant factor

Irrigable area is the amount of landscaped area on the property that receives regular watering. Evapotranspiration is the amount of water that is lost each day due to evaporation and plant transpiration. Evaporation will vary due to factors such as wind, humidity, and temperature. Lastly, the plant factor equates to the specific amount of irrigation water required by each type of plant in your yard.


MNWD provides this evapotranspiration tool to help our customers better understand areas where ET levels are higher, and how it plays a role in your residential outdoor water budget.



Commercial Water Budgets

Commercial water budgets are calculated based on a three-year rolling average of each commercial customer’s monthly use. If your business has landscape irrigation needs, the water budget is calculated based on the size of the landscaped area and real-time localized weather data, among other factors.


Recycled Water, Potable Water, and Public Spaces

If recycled water is in use, commercial outdoor water budgets are calculated similarly to residential outdoor water budgets, but with a higher plant factor to account for areas with more turf. The same calculation applies to water budgets for potable water and public spaces.




Water Budget Based Rate Structure and Cost Allocations

Customers whose water use remains within their water budgets are billed at the lowest available rates, and customers who exceed their water budgets are billed at higher rates for the amount of water they use above their water budget. All water rate revenue in excess of $2.27 per billing unit (BU), which is the District’s marginal cost of water, will be designated for the Water Efficiency Fund. The chart, below, depicts how funds are allocated based on usage during normal water supply conditions.

Water Efficiency Fund

To most effectively manage water resources, the Water Efficiency Fund was created to help promote water conservation and water use efficiency programs. The program implements rebates for water efficient fixtures and appliances, water conservation educational campaigns, and more to promote drought-friendly practices within the local community. The Water Efficiency Fund receives most of its funding through the “non‐budget tiers” (currently Tiers 3, 4, and 5) of water and recycled water rate revenue. The greater the demand for water, the greater the need to expand the Conservation and Water Use Efficiency Programs and incur related costs. These incremental cost increases are therefore proportionately allocated to customers who use water within Tiers 3, 4, and 5.

Variances & Adjustments

We’re committed to ensuring that our customers have a customized water budget that promotes efficiency while providing the water necessary to meet their everyday needs. Should legitimate reasonable need for additional water arise for your home or business, our Water Budget Based Rate Structure includes simple steps to adjust your established water budget. Simply fill out a Variance Request, either residential or commercial based on your needs, or call the District to provide us with some basic information and we will guide you through the process.

For more information about your water budget, please contact the MNWD Water Efficiency Department at (949) 448-4025.