Upper Ammonoosuc River Near Groveton, NH

USGS Site No: 01130000Upper Ammonoosuc River • Coos County, NH

Upper Ammonoosuc River Near Groveton, NH on the Upper Ammonoosuc River is currently at 292 cfs (Normal — 38th percentile for this date) . Gage height: 2.50 ft.

Reading from

292
CFS Discharge
2.50
Gage Height (ft)
Normal
Flow Condition
Normal
Flood Status

Historical Percentile Comparison

Today's discharge compared to the long-term record for June 11 at this station. Percentile rank shows what fraction of historical years had lower flow on this date.

Percentile Label CFS Threshold Today's Flow
10th Very Low threshold 185
25th Low threshold 228
50th (Median) Normal (median) 353 Today: 292 cfs
75th High threshold 469
95th Very High threshold 1,160

30-Day Hydrograph

Recent discharge plotted against the historical 10th–95th percentile envelope for the same calendar days. Source: USGS daily values + long-term statistics.

5.2k 2.6k 0 cfs Apr 6 May 28
10th–95th historical Day-of-year median Recent discharge

30-Day Flow History

Date Discharge (CFS) Gage Ht (ft)
May 28, 2026 326
May 27, 2026 435
May 26, 2026 656
May 25, 2026 558
May 24, 2026 309
May 23, 2026 321
May 22, 2026 366
May 21, 2026 429
May 20, 2026 507
May 19, 2026 597
May 18, 2026 695
May 17, 2026 919
May 16, 2026 1,500
May 15, 2026 1,730
Apr 21, 2026 1,370
Apr 20, 2026 1,830
Apr 19, 2026 1,950
Apr 18, 2026 2,680
Apr 17, 2026 3,440
Apr 16, 2026 2,390
Apr 15, 2026 2,530
Apr 14, 2026 2,080
Apr 13, 2026 1,350
Apr 12, 2026 1,230
Apr 11, 2026 1,420
Apr 10, 2026 936
Apr 9, 2026 914
Apr 8, 2026 1,050
Apr 7, 2026 1,440
Apr 6, 2026 2,050

Station Information

USGS Site No
01130000
State
NH
County
Coos County
Coordinates
44.6251, -71.4690
Drainage Area
232 mi²
Datum (ft)
916.4
HUC Code
01080101
View on USGS NWIS →

Flood Stage Thresholds

Action Stage
6.5 ft
Flood Stage
7.5 ft
Moderate Flood
9.0 ft
Major Flood
10.0 ft

Currently 5.00 ft below flood stage.

Recent Extremes

Max discharge
3,440 cfs
Apr 17, 2026
Min discharge
32 cfs
Sep 21, 2025
Days at flood stage
0

Computed from the local daily-values archive.

Nearby Gauges