Riverside Public Utilities is the city's own utility, and its report says it blends its water sources at one central location before the water reaches homes. That is why the figure is tight: the report's range runs only from 180 to 210 mg/L around an average of 197 mg/L. Not every Riverside address is an RPU customer. State water-system boundary data suggests other suppliers, mainly Western Municipal Water District, serve parts of ZIP codes 92503, 92504, 92507 and 92508, and Western's report for its Riverside area lists softer water than RPU's. Your water bill names your supplier.
What 12 gpg means
Hardness is measured in grains per gallon (gpg). The U.S. Geological Survey calls water hard from 7.1 to 10.5 and very hard above 10.5. The utility prints 12, which is in the very hard band. Its average of 197 mg/L is also above the 180 mg/L line USGS uses for very hard, though not by a wide margin. Very hard water leaves scale on fixtures, spots on glass and buildup inside water heaters.
Where your water comes from
Riverside Public Utilities is the city's own utility. Its report lists groundwater from the Bunker Hill and Riverside basins, blended at one central location before distribution. If your water bill comes from Riverside Public Utilities, the figure above is the one that applies to you. If it comes from another supplier, read that supplier's report instead.
Riverside's rule on water softeners
Riverside allows residential water softeners with conditions. Under Riverside Municipal Code section 14.12.245, a residential softener may be installed in two cases. The first is a unit that regenerates off site. The second is a unit that discharges to the home's waste system and meets state equipment standards: it regenerates only when needed, it has a certified salt efficiency (grains of hardness removed per pound of salt) of at least 4,000, and water-saving devices are installed with it. The code also requires a contractor holding a C-55 or C-36 license to file a certification with the city's Building Division.
The code also lets the city limit or prohibit softeners that discharge to the sewer, but only after specific findings. We have not found that the city has made those findings. This is a plain-words summary of the code as published, not legal advice, so confirm with the city's Building and Safety division before you buy. What Nuvia recommends in Riverside has to fit within the code.
What Nuvia does in Riverside
We offer a free in-home water analysis so you can see your own tap's numbers next to the utility's average. Book it with the form below. If you want to read first, start with water softeners and conditioners, whole-house water filtration or reverse osmosis drinking water.
Nearby cities
Sources
- Riverside Public Utilities Water Quality Report (2025 water data)
- Riverside Municipal Code Title 14, Chapter 14.12 (Municode)
- City of Riverside Residential Water Softener Guidelines (Building and Safety handout)
- Western Municipal Water District Consumer Confidence Report (Riverside service area columns)
- USGS Water Science School: Hardness of water
Questions people ask
How hard is the water in Riverside?
Riverside Public Utilities prints 12 gpg in its report, which is 197 mg/L on average, with samples from 180 to 210 mg/L. That is in the very hard band on the USGS scale.
Why is Riverside's number so consistent?
The utility's report says it blends its water sources at one central location before the water is distributed. That is why the range in the report is narrow.
Is the water the same in every part of Riverside?
Not if another supplier serves you. State water-system boundary data suggests Western Municipal Water District and other suppliers serve parts of ZIP codes 92503, 92504, 92507 and 92508. Western's report for its Riverside area lists softer water than the utility's. Your water bill names your supplier.
Can I install a water softener in Riverside?
Riverside's code allows residential water softeners with conditions. The unit has to regenerate off site, or discharge to the home's waste system and meet state equipment standards, and a C-55 or C-36 contractor has to certify the installation to the city's Building Division. Confirm with the city before you buy.
Has Riverside banned water softeners?
No. The code lets the city limit or prohibit softeners that discharge to the sewer, but only after specific findings, and we have not found that the city has made them. This is a summary of the code as published, not legal advice.
Does the in-home water analysis cost anything?
No. Nuvia Water offers it free. Book it with the form on this page or with the Book button.
Book your free water analysis today.
A Nuvia specialist tests your water at your tap and shows you the numbers.