Rivermatics

2 USGS Streamgages · Colorado River system

Bill Williams River flows and levels

Bill Williams River is gauged at 2 USGS streamgages in Arizona, each tracked by Rivermatics. The mainstem runs about 156 miles (250 km) from headwaters to outlet. It drains into the Colorado River system. Drainage area at the gauges ranges from 4,633 square miles at Bill Williams River below Alamo Dam, AZ up to 5,337 at Bill Williams River near Parker, AZ. The gauged reach falls about 453 feet, from 954 feet down to 502. Rivermatics issues a daily machine-learned 14-day flow outlook for every one of them.

Gauges on this river, upstream to downstream

Ordered by drainage area, which is how far down the river each gauge sits. April and July figures are long-term median daily flows for that month from the USGS record — historical normals, not a forecast and not today's reading.

USGS streamgages on this river, ordered upstream to downstream
Gauge State Drainage sq mi Elevation ft April p50 cfs July p50 cfs Forecast
Bill Williams River below Alamo Dam, AZ AZ 4,633 954 25.2 24.9 14-day
Bill Williams River near Parker, AZ AZ 5,337 502 9.7 0.7 14-day

Typical flow by month at Bill Williams River near Parker, AZ

The furthest-downstream gauge on this river, so the fullest flow it carries here. Long-term daily discharge percentiles from the USGS record (up to 38 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 0 10.6 23.5
February 0 11.9 263.4
March 2.1 11.9 722.3
April 0.8 9.7 297
May 0 6.4 39.9
June 0 3.2 18.6
July 0 0.7 15.2
August 0 0.2 13.7
September 0 1.5 15.8
October 0 4.2 16.6
November 0 8.1 19.2
December 0 9.6 20.4

All values in cubic feet per second (cfs).

Common questions

When does the Bill Williams River run highest?
February, on the long-term record at Bill Williams River near Parker, AZ — the furthest-downstream gauge Rivermatics tracks on this river. Median daily flow there is about 11.9 cfs that month, against 0.2 cfs in August, the lowest. Upstream gauges peak on their own schedule; the table on this page gives April and July for each.
How many gauges are on the Bill Williams River?
Rivermatics tracks 2 USGS streamgages on the Bill Williams River, across Arizona. Each has its own page with the site's full flow record and monthly normals. The river may carry other gauges that publish neither daily values nor discharge statistics; those are not tracked here.
Is there a flow forecast for the Bill Williams River?
Yes, at 2 of the 2 gauges. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on each basin's observed flows, weather and snowpack, and issues a daily 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 each gauge's live screen.
What river system is the Bill Williams River part of?
The Bill Williams River drains into the Colorado River system — it is a tributary somewhere in that chain, following the flowpath down to its terminal river. Rivermatics builds this from the USGS/geoconnex reference-mainstem network rather than from names.
Can I use Bill Williams River 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.

Other rivers in the Colorado River system

Browse nearby gauges by state