Before anything else, a data check. For every zone, the reading collected over the wireless mesh matches the meter reading printed on the city bill, which means the database can predict each bill weeks before it arrives.
| Zone | Bill cycle | Billed | Metered (DB) | Match | Bill amount |
|---|---|---|---|---|---|
| Zone 1 | Jul 9 – Aug 7 | 29,000 gal | 29,584 gal | ✓ | $200.08 |
| Zone 2 | Jul 9 – Aug 7 | 23,000 gal | 22,443 gal | ✓ | $166.18 |
| Zone 3 | Jul 9 – Aug 7 | 21,000 gal | 21,027 gal | ✓ | $189.08 |
| Zone 4 | Jul 9 – Aug 7 | 18,000 gal | 16,944 gal | ✓ | $137.93 |
| Zone 5 | Jul 9 – Aug 7 | 22,000 gal | 22,098 gal | ✓ | $169.93 |
The city rounds bill readings down to whole thousands of gallons, which explains the small differences. Zone 3's August statement arrived after the meter network had already predicted it: the database projected 21,027 gallons and the city billed 21,000.
Monthly bill totals in thousands of gallons. Zones 1 and 5 drive the community-wide reduction; Zone 3 moved the other way.
| Zone | Year | May | Jun | Jul | Aug | Sep | May–Aug |
|---|---|---|---|---|---|---|---|
| 1 | 2025 | 39 | 51 | 51 | 66 | 26 | 207 |
| 2026 | 20 | 41 | 41 | 29 | · | 131 | |
| 2 | 2025 | 11 | 13 | 20 | 20 | 6 | 64 |
| 2026 | 10 | 18 | 23 | 23 | · | 74 | |
| 3 | 2025 | 22 | 22 | 15 | 21 | 9 | 80 |
| 2026 | 16 | 27 | 27 | 21 | · | 91 | |
| 4 | 2025 | 10 | 15 | 21 | 18 | 4 | 64 |
| 2026 | 16 | 20 | 18 | 18 | · | 72 | |
| 5 | 2025 | 46 | 50 | 28 | 25 | 5 | 149 |
| 2026 | 16 | 26 | 22 | 22 | · | 86 |
Values are kgal per billing cycle, labeled by statement month. 2026 September cycles have not been billed yet.
Boulder assigns each irrigation account a water budget per cycle; usage beyond it is billed at steep penalty tiers ($7.53 to $37.64 per kgal instead of $5.65). Only Zone 3 exceeds its budget.
Billing cycle July 9 to August 7, 2026. Zone 3 went over its budget for the second cycle in a row: it used 21,000 gallons against a 17,000 gallon budget, and the overage pushed 4,000 gallons into the $15.06 tier for a $189.08 bill. In July it used 27,000 against a 19,000 budget and paid $262.50. The city has lowered its budget to 16,000 gallons for the next cycle.
How much water each zone actually used by calendar month, compared with what its irrigation controller program should deliver (minutes of runtime multiplied by the measured flow rate).
| Zone | Program | Jun (gal) | Jul (gal) | Aug 1–11 | Jul gal/day | Schedule gal/day | Fit |
|---|---|---|---|---|---|---|---|
| 1 | M W S · 80 min · 28.4 GPM | node online Jul 1 | 34,627 | 11,210 | ~1,190 | 974 | +22% over program |
| 2 | T T S (+Su) · 55 min · 23.1 GPM | 15,504 | 23,679 | 9,038 | 764 | ~680 | matches schedule |
| 3 | M T W T S · 30 min · 19.4 GPM ×2 programs | 26,686 | 26,228 | 4,593 | 846 | ~580 | second program running |
| 4 | T T S S · 60 min · 16.0 GPM | 20,390 | 19,199 | 6,617 | 619 | 913 pre-repair | repaired Jul 21 |
| 5 | M W S · 60 min · 31.2 GPM | 24,395 | 24,045 | 9,223 | 776 | 801 | matches schedule |
Volumes are the change in each meter's cumulative reading over the period. Zone 1's node came online July 1, so its July figure covers July 1 to July 31 and it has no June data. In the Program column, the letters are the days of the week the zone waters.
This zone saved the most water: its August bill was 29,000 gallons, down from 65,000 for the same cycle last year. Even so, it still delivers about 22% more water than its program calls for. Watering days log 2,300 to 3,500 gallons where 80 minutes at 28.4 gallons per minute should use about 2,272. Unexplained extra runs on Wednesday evenings around 9:30 PM are the likely cause.
This zone runs almost exactly as programmed, using about 1,220 gallons per watering day against a predicted 1,272. Its 16% rise over 2025 matches a Sunday watering day that was added on purpose in July, and it still uses only about half of its city budget.
This is the zone that needs attention. Its July use nearly doubled compared with last year (27,000 gallons versus 15,000), and the August bill confirms a second straight overage: 21,000 gallons against a 17,000 gallon budget, for $189.08. It is the only zone paying penalty rates, and the city has lowered its budget to 16,000 gallons for the next cycle. The meter data shows the cause clearly: the controller runs two watering programs on the same mornings, one starting at 4:00 AM and another at 5:00 AM, and it is also watering on days it was not meant to.
A valve repair around July 21 shows up plainly in the data: watering days dropped from about 1,200 gallons to about 940. That 21% cut kept the August cycle at 18,000 gallons, comfortably under budget.
This zone runs exactly as scheduled, using about 1,850 gallons per watering day against a predicted 1,869, and it improved the most of any zone: down 42% from 2025. At 79% of its budget, though, it has the least room to spare of the zones that are within budget.