USGS Streamgage 06600100
Floyd River at Alton, IA
Floyd River at Alton, IA is USGS streamgage 06600100 in Iowa, monitoring river discharge in hydrologic subbasin 10230002. It sits on the Floyd River, alongside 1 other gauge Rivermatics tracks on the same river. It drains a watershed of about 268 square miles. Discharge records at this site go back to 1953. Typical flow runs near 49.8 cfs in July and 87.7 cfs in April, with the higher of the two arriving in April. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.
View live conditions & forecast →
Gauge details
- State
- Iowa
- Drainage area
- 268 sq mi
- Gauge elevation
- 1,278 ft
- Subbasin (HUC-8)
- 10230002
- Coordinates
- 42.98281, -96.00033
- USGS site number
- 06600100
- Records begin
- 1953-06-01 (73 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Floyd River at Alton, IA. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.
| Date | Low p10 | Expected p50 | High p90 | Range |
|---|---|---|---|---|
| 131 | 183 | 259 | ||
| 70.3 | 114 | 189 | ||
| 49.4 | 83.3 | 146 | ||
| 39.8 | 69.9 | 138 | ||
| 36.3 | 78 | 253 | ||
| 44 | 137 | 604 | ||
| 62.4 | 258 | 1,247 | ||
| 87.7 | 336 | 1,350 | ||
| 83.5 | 291 | 1,037 | ||
| 74 | 236 | 735 | ||
| 58.6 | 171 | 508 | ||
| 43.4 | 123 | 383 | ||
| 37.1 | 94.2 | 277 | ||
| 32.4 | 74.9 | 204 |
All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 71 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | 0.6 | 12.2 | 83.9 | |
| February | 0.4 | 19.1 | 144.7 | |
| March | 5.2 | 58 | 448.5 | |
| April | 9.6 | 87.7 | 406.8 | |
| May | 9.7 | 92.4 | 416.5 | |
| June | 10 | 102.5 | 542.4 | |
| July | 4.9 | 49.8 | 264.7 | |
| August | 2.4 | 20.3 | 128.3 | |
| September | 1.3 | 14.2 | 117.7 | |
| October | 2 | 17.2 | 188.5 | |
| November | 2.4 | 19.3 | 139.2 | |
| December | 1.7 | 16.7 | 113.6 |
All values in cubic feet per second (cfs).
Common questions
- When does Floyd River at Alton, IA normally run highest?
- June, on the long-term record. The median daily flow that month is about 102.5 cfs, against 12.2 cfs in January, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Floyd River at Alton, IA?
- It depends on the month. In January, half of days historically fall near 12.2 cfs, with the middle 80% of days between 0.6 and 83.9 cfs. The month-by-month table on this page gives the full range.
- How long has Floyd River at Alton, IA been measured?
- Discharge records at USGS site 06600100 begin in 1953, about 73 years, covering roughly 9,200 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for Floyd River at Alton, IA?
- Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
- Where is Floyd River at Alton, IA?
- The gauge sits at 42.98281, -96.00033, in Iowa, in hydrologic subbasin 10230002, at an elevation of about 1,278 feet, draining roughly 268 square miles.
- Can I use Floyd River at Alton, IA data for flood or safety decisions?
- No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.
Upstream and downstream on the Floyd River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Floyd River in full.
- Floyd River at Alton, IA this page
- Floyd River at James, IA 886 sq mi