This winter our area has experienced dry conditions, leading to questions about how to best care for our trees.
In Boulder, our trees provide many benefits to the environment and our community, and are critical to mitigating climate change. Just like we use more water in the summer to care for them, in dry winters, additional watering is essential to keep trees healthy.
But how will watering trees in the winter, something we don’t think about in wetter years, impact your utility bill?
The city provides three separate water-related services: stormwater, drinking water and wastewater. Stormwater is a flat fee not impacted by winter water use. Drinking Water use is directly measured and billed, so it’s easy to see that any water use, such as watering trees, has an associated cost. What may be less well known is that winter tree watering can also potentially affect wastewater charges.
Wastewater Billing and Annual Winter Consumption, explained
For residential customers, wastewater charges are based on your actual or average water use from the previous December through March, whichever is lower. This is called Average Winter Consumption (AWC). Because of this, winter outdoor water use, such as watering trees, could potentially affect the amount of wastewater used to calculate your monthly utility bill.
Typical guidance for winter tree watering is about 150 gallons of water every few weeks for a 10-inch diameter tree during dry periods. For most customers, this would not change a wastewater bill because charges are billed in 1,000-gallon increments. Any usage below 1,000 is carried over to the next month's usage. Only customers who are near the top of a 1,000-gallon tier might be impacted. To see an increase, water use would need to move into the next 1,000 gallon tier for all four winter months, which would result in an $8.86 monthly increase.
Since precipitation can vary dramatically from month to month, it is not yet clear whether watering will be necessary throughout the winter. It may or may not have any impact on AWC or future wastewater utility bills. We will be monitoring usage closely throughout the winter and provide and update to the Water Resources Advisory Board once we better understand the effects of winter watering on AWC this season.
Tips for conservation
To help minimize winter water use, be thoughtful and conserve where you can. Here are some tips:
- Water trees most at risk from dry conditions as needed (every few weeks when it’s dry)
- Water only when temperatures are above 40°F and the ground isn’t frozen
- Apply water slowly at the root zone and avoid runoff
- Focus on trees, not grass
- Reuse indoor water, like water collected while waiting for the shower to warm up, for tree watering
For more information on tree watering and overall tree care, check out the tree care and watering information on our website.
Community support
We know that even a slight increase in your utility bill can be impactful. Assistance programs are available for households experiencing financial hardship. Contact Utilities Billing to explore available options and visit our community support webpage.
A changing climate
As winter watering becomes more common with a changing climate, the city will continue reviewing how outdoor winter water use fits into wastewater billing. A Utilities rate study is beginning, and there will be opportunities for public input.