Castle Rock water and sewer rates
Who supplies water to Castle Rock houses, what it costs, and how the sewer charge works.
Castle Rock Water
Castle Rock Water 2026 residential rates: water monthly service charge $11.49 and renewable water monthly service charge $36.30 (5/8 by 3/4 inch meter); water volumetric rates per 1,000 gallons of $3.39 (Tier 1, AWMC) and $6.91 (Tier 2, irrigation season); Tier 3 (excess) is $10.31 in irrigation season and $6.91 in winter; the surcharge over 40,000 gallons is $10.31.
| Use a month | Price per 1,000 gallons |
|---|---|
| Fixed charge | $47.79 a month |
| 0 to 5 thousand gallons | $3.39 |
| 5 to 40 thousand gallons | $6.91 |
| 40 to more | $10.31 |
- Source
- In 2025 about 70% came from 63 deep Denver Basin groundwater wells; the other 30% from shallow alluvial wells, Plum Creek and East Plum Creek diversions, and imported WISE water.
- Hardness
- Moderately hard: 100 ppm on average in 2025 (range 61 to 182 ppm).
- Lead
- In 2025 sampling the 90th-percentile lead level was 2 ppb both rounds (102 sites, none above the 15 ppb action level; 100 sites, 1 above).
- Violations
- Two non-health-based violations for failure to monitor and/or report.
Sewer
Wastewater is on the Castle Rock Water bill: an $8.65 monthly service charge (5/8 by 3/4 inch meter) plus $6.13 per 1,000 gallons of your average winter monthly consumption (November through February), reset each April.
Other charges on the utility bill
- Stormwater (single-family attached or detached residence): $8.79 a month
Ways to pay less
- Seniors over 65: Castle Rock Water senior discount. Castle Rock Water gives a senior citizen discount of $3 per single-family equivalent per month to anyone over the age of 65. How: Call Castle Rock Water at 303-660-1373 to apply.
- Replace old toilets: up to $150 each. Castle Rock Water rebates the cost of an ultra-high-efficiency toilet rated 0.8 gallons per flush or less, up to $150 per toilet and up to four toilets per address, excluding installation, taxes and shipping. How: Fill in the Toilet Retrofit Rebate Application online form; the old toilet is turned in to Castle Rock Water.
- Swap sprinkler spray nozzles for rotary nozzles. Castle Rock Water offers rebates of up to $5 each for replacing fixed-spray nozzles with rotary nozzles, purchased, installed and applied for in the same rebate year. How: Fill in the Rotary Nozzle Retrofit Rebate Application online form.
- Replace lawn with ColoradoScape (2027 program). The residential ColoradoScape rebate paid $3.25 per square foot for replacing at least 400 square feet (or the whole front yard) of healthy high-water-use plants. The 2026 program is closed; 2027 details come out in April 2027. How: Apply and get the site visit before starting the renovation.
Pay or manage it
Sources
- Castle Rock Water 2026 utility rate and fee schedule
- Castle Rock Water: water billing rates and administrative fees
- Castle Rock Water 2026 water quality report
Checked October 21, 2026. Every number here comes from the public sources listed, matched by our checker.
Rates change every year; this page shows when it was last checked. Nothing here is legal, tax or insurance advice.