Skip Main Navigation
Skip to Content

Source Water Protection

Arvada’s drinking water comes from two surface water sources

1) Denver Water’s North Collection System is City of Arvada’s year-round source, supplying approximately 75% of the drinking water supply. This water is fresh mountain snowmelt and is collected from the Fraser and Williams Fork River valleys then transported to South Boulder Creek through the Moffat Tunnel. Water is diverted downstream of Gross Reservoir through the South Boulder Diversion Canal to Ralston Reservoir, then either piped to the Ralston Water Treatment Plant or delivered to Arvada Reservoir via Ralston Creek.

2) Clear Creek provides the remainder of the City’s water supply which is diverted through one of three canals to the Arvada Reservoir in the spring/summer months when water demands peak. Water from the Arvada Reservoir can be treated at either Ralston Water Treatment Plant or the Arvada Water Treatment Plant.

Click on image for larger view

map of Arvada water sources

Actions that help protect source water

Arvada residents depend on a reliable supply of safe, high quality drinking water. Protecting our drinking water is essential to preserve our own health and economy and that of future generations. The City and residents both have important roles to play in protecting the source water on which we all depend. 

Click on images for larger view

English version                                          Spanish version

sign about source waterSpanish version of sign about source water







The City of Arvada Water Quality staff undertake a variety of measures to protect our source water such as:

  • Monitoring activity in our watersheds.
  • Monitoring our influent canals and Arvada Reservoir frequently for a variety of water quality parameters.
  • Managing noxious weeds and harmful algae in and around the reservoir.
  • Protecting our drinking water source from microbial and chemical contaminants by allowing only non-motorized and non-contact recreation in Arvada Reservoir. 
  • Performing watercraft inspections to help stop the spread of invasive species like Zebra and Quagga mussels.
  • Participating with and supporting local/regional wildfire protection efforts in Clear Creek County, Jefferson County, and Boulder County.
  • Communicating regularly with Denver Water regarding operational changes to water supply.
  • Communicating with CO Legacy Land and receiving monitoring and operational information regarding legacy mines.
  • Planning for future projects, educational opportunities, and best management plan implementations.

Residents can do their part to protect our source waters by:

  • After recreating in the reservoir, follow the Clean, Drain, Dry procedure for all equipment: .
  • Properly using and disposing of household hazardous chemicals and pharmaceuticals.
  • Minimizing the use of lawn and garden chemicals. 
  • Keeping unwanted materials out of storm drains. 
  • If you are able, consider volunteering to Adopt-A-Street.
  • Volunteering as a Ranger for Arvada Reservoir.

Arvada’s Source Water Protection Plan

In 2021, Arvada published a Source Water Protection Plan (SWPP). This work was done in conjunction with CDPHE and CRWA, and the City earned a $5000 grant for the implementation. Water Quality staff used the grant money towards a new monitoring boat and an educational sign at the Arvada Reservoir.  Read the SWPP.

boat by a ponnd


Featured Video

Click on the preview below to watch.

Watch This Video Preview of YouTube Video

Get more videos in our video gallery or on YouTube.


Source Water Protection