USGS Streamgage 06471500
Elm River at Westport, SD
Elm River at Westport, SD is USGS streamgage 06471500 in South Dakota, monitoring river discharge in hydrologic subbasin 10160004. It sits on the Elm River, alongside 2 other gauges Rivermatics tracks on the same river. It drains a watershed of about 1,505 square miles. Discharge records at this site go back to 1945. Typical flow runs near 11.1 cfs in July and 48.1 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
- South Dakota
- Drainage area
- 1,505 sq mi
- Gauge elevation
- 1,314 ft
- Subbasin (HUC-8)
- 10160004
- Coordinates
- 45.65611, -98.49667
- USGS site number
- 06471500
- Records begin
- 1945-10-01 (81 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Elm River at Westport, SD. 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 |
|---|---|---|---|---|
| 13.9 | 15.3 | 16.9 | ||
| 12.1 | 14.4 | 16.6 | ||
| 11 | 13.9 | 16.8 | ||
| 10.3 | 13.6 | 17.8 | ||
| 9.5 | 13 | 17.3 | ||
| 8.8 | 12.6 | 17.2 | ||
| 9.2 | 13.3 | 19.5 | ||
| 8.7 | 13.4 | 20.2 | ||
| 8.1 | 13.1 | 20.9 | ||
| 7.6 | 12.7 | 20.9 | ||
| 7.1 | 12.2 | 21.1 | ||
| 6.7 | 11.6 | 20.1 | ||
| 6.3 | 11 | 18.6 | ||
| 5.9 | 10.6 | 17.9 |
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 81 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 | 0.8 | 3.2 | 7.7 | |
| February | 0.7 | 3.5 | 13.8 | |
| March | 1.6 | 18 | 544 | |
| April | 2.8 | 48.1 | 937.8 | |
| May | 2.8 | 31.5 | 351.3 | |
| June | 2 | 16.1 | 227.2 | |
| July | 3 | 11.1 | 176.5 | |
| August | 2 | 7.7 | 75.2 | |
| September | 1.1 | 5.6 | 29.6 | |
| October | 0.9 | 6 | 22.8 | |
| November | 1.5 | 5.4 | 15.4 | |
| December | 1.4 | 4.1 | 10.4 |
All values in cubic feet per second (cfs).
Common questions
- When does Elm River at Westport, SD normally run highest?
- April, on the long-term record. The median daily flow that month is about 48.1 cfs, against 3.2 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 Elm River at Westport, SD?
- It depends on the month. In January, half of days historically fall near 3.2 cfs, with the middle 80% of days between 0.8 and 7.7 cfs. The month-by-month table on this page gives the full range.
- How long has Elm River at Westport, SD been measured?
- Discharge records at USGS site 06471500 begin in 1945, about 81 years, covering roughly 9,080 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for Elm River at Westport, SD?
- 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 Elm River at Westport, SD?
- The gauge sits at 45.65611, -98.49667, in South Dakota, in hydrologic subbasin 10160004, at an elevation of about 1,314 feet, draining roughly 1,505 square miles.
- Can I use Elm River at Westport, SD 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 Elm River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Elm River in full.
- Elm River near Frederick, SD 282 sq mi
- Elm River at Westport, SD this page
- Elm River near Ordway, SD 1,520 sq mi