Columbia River below Bonneville Dam water level

What this means

Low water at Columbia River below Bonneville Dam: the gauge reads 7.21 ft, far below normal for mid-October.

The median for mid-October is 9.72 ft, based on 45 years of readings, so the river stage is 2.51 ft below typical. On the same day last year the reading was 8.90 ft, a difference of −1.69 ft.

It is still going down, by 0.06 ft over the past 24 hours. Without real rain upstream, that is unlikely to change quickly. The 30-day range is 6.10 ft – 10.10 ft.

Fall is often low-water season on rivers, and it usually takes a few days of steady rain to change that.

Compared with 45 years of daily readings for this time of year. How to read levels

Key numbers

Median for this date

9.72 ft2.51 ft below the median for this date

Normal for this date

8.25 ft – 12.67 ft8 years in 10 fall in this range (45 years of records)

Same day last year

8.90 ft−1.69 ft

Lowest and highest in 30 days

6.10 ft – 10.10 ft

Lowest and highest in 12 months

6.84 ft – 22.97 ft