MATTOLE RIVER - ETTERSBURG (ETTC1)
Latitude: 40.14º NLongitude: 123.99º WElevation: 579 FeetForecast Type: Unofficial Location
Location: Humboldt County in CaliforniaBulletin Group: North CoastRiver Group: North Coast
Issuance Time: Apr 21 2026 at 7:58 AM PDTNext Issuance: Apr 22 2026 at 9:00 AM PDT
Action/Monitor: N/A Minor Flood: N/A Moderate Flood: N/A Major Flood: N/A

# Tabular Observed and Forecast Hydrograph Information
#
# Location: Mattole River - Ettersburg (ETTC1)
#
# File Generation Time:  04/21/2026 at 08:03 AM PDT
# Data Interval:  1 Hour
#
# Most Recent Date & Time of Maximum Observed:  04/20/2026 at 06:00 PM PDT
# Maximum Observed Stage:                       9.71 Feet
# Maximum Observed Flow:                        154 cfs
#
# Earliest Date & Time of Maximum Forecast:     04/21/2026 at 08:00 PM PDT
# Maximum Forecast Stage:                       10.22 Feet
# Maximum Forecast Flow:                        243 cfs
#
# OBSERVED
#
# Date & Time  (Local)    Stage (Feet)     Flow (cfs)     Trend     Observed Status
# ---------------------------------------------------------------------------------
  04/16/2026 08 AM PDT            9.66            146                Not Applicable
  04/16/2026 09 AM PDT            9.65            144         -      Not Applicable
  04/16/2026 10 AM PDT            9.64            143         -      Not Applicable
  04/16/2026 11 AM PDT            9.63            141         -      Not Applicable
  04/16/2026 12 PM PDT            9.63            141         0      Not Applicable
  04/16/2026 01 PM PDT            9.63            141         0      Not Applicable
  04/16/2026 02 PM PDT            9.61            138         -      Not Applicable
  04/16/2026 03 PM PDT            9.62            140         +      Not Applicable
  04/16/2026 04 PM PDT            9.60            137         -      Not Applicable
  04/16/2026 05 PM PDT            9.60            137         0      Not Applicable
  04/16/2026 06 PM PDT            9.59            135         -      Not Applicable
  04/16/2026 07 PM PDT            9.58            134         -      Not Applicable
  04/16/2026 08 PM PDT            9.58            134         0      Not Applicable
  04/16/2026 09 PM PDT            9.58            134         0      Not Applicable
  04/16/2026 10 PM PDT            9.57            132         -      Not Applicable
  04/16/2026 11 PM PDT            9.57            132         0      Not Applicable
  04/17/2026 12 AM PDT            9.56            131         -      Not Applicable
  04/17/2026 01 AM PDT            9.55            129         -      Not Applicable
  04/17/2026 02 AM PDT            9.56            131         +      Not Applicable
  04/17/2026 03 AM PDT            9.55            129         -      Not Applicable
  04/17/2026 04 AM PDT            9.55            129         0      Not Applicable
  04/17/2026 05 AM PDT            9.54            128         -      Not Applicable
  04/17/2026 06 AM PDT            9.53            126         -      Not Applicable
  04/17/2026 07 AM PDT            9.53            126         0      Not Applicable
  04/17/2026 08 AM PDT            9.53            126         0      Not Applicable
  04/17/2026 09 AM PDT            9.53            126         0      Not Applicable
  04/17/2026 10 AM PDT            9.53            126         0      Not Applicable
  04/17/2026 11 AM PDT            9.52            125         -      Not Applicable
  04/17/2026 12 PM PDT            9.52            125         0      Not Applicable
  04/17/2026 01 PM PDT            9.52            125         0      Not Applicable
  04/17/2026 02 PM PDT            9.53            126         +      Not Applicable
  04/17/2026 03 PM PDT            9.52            125         -      Not Applicable
  04/17/2026 04 PM PDT            9.52            125         0      Not Applicable
  04/17/2026 05 PM PDT            9.51            124         -      Not Applicable
  04/17/2026 06 PM PDT            9.50            122         -      Not Applicable
  04/17/2026 07 PM PDT            9.50            122         0      Not Applicable
  04/17/2026 08 PM PDT            9.49            121         -      Not Applicable
  04/17/2026 09 PM PDT            9.49            121         0      Not Applicable
  04/17/2026 10 PM PDT            9.49            121         0      Not Applicable
  04/17/2026 11 PM PDT            9.48            119         -      Not Applicable
  04/18/2026 12 AM PDT            9.47            118         -      Not Applicable
  04/18/2026 01 AM PDT            9.47            118         0      Not Applicable
  04/18/2026 02 AM PDT            9.47            118         0      Not Applicable
  04/18/2026 03 AM PDT            9.47            118         0      Not Applicable
  04/18/2026 04 AM PDT            9.46            117         -      Not Applicable
  04/18/2026 05 AM PDT            9.46            117         0      Not Applicable
  04/18/2026 06 AM PDT            9.45            115         -      Not Applicable
  04/18/2026 07 AM PDT            9.45            115         0      Not Applicable
  04/18/2026 08 AM PDT            9.44            114         -      Not Applicable
  04/18/2026 09 AM PDT            9.45            115         +      Not Applicable
  04/18/2026 10 AM PDT            9.45            115         0      Not Applicable
  04/18/2026 11 AM PDT            9.45            115         0      Not Applicable
  04/18/2026 12 PM PDT            9.44            114         -      Not Applicable
  04/18/2026 01 PM PDT            9.45            115         +      Not Applicable
  04/18/2026 02 PM PDT            9.45            115         0      Not Applicable
  04/18/2026 03 PM PDT            9.45            115         0      Not Applicable
  04/18/2026 04 PM PDT            9.44            114         -      Not Applicable
  04/18/2026 05 PM PDT            9.44            114         0      Not Applicable
  04/18/2026 06 PM PDT            9.43            112         -      Not Applicable
  04/18/2026 07 PM PDT            9.42            111         -      Not Applicable
  04/18/2026 08 PM PDT            9.43            112         +      Not Applicable
  04/18/2026 09 PM PDT            9.42            111         -      Not Applicable
  04/18/2026 10 PM PDT            9.41            110         -      Not Applicable
  04/18/2026 11 PM PDT            9.42            111         +      Not Applicable
  04/19/2026 12 AM PDT            9.41            110         -      Not Applicable
  04/19/2026 01 AM PDT            9.41            110         0      Not Applicable
  04/19/2026 02 AM PDT            9.40            108         -      Not Applicable
  04/19/2026 03 AM PDT            9.40            108         0      Not Applicable
  04/19/2026 04 AM PDT            9.40            108         0      Not Applicable
  04/19/2026 05 AM PDT            9.40            108         0      Not Applicable
  04/19/2026 06 AM PDT            9.39            107         -      Not Applicable
  04/19/2026 07 AM PDT            9.39            107         0      Not Applicable
  04/19/2026 08 AM PDT            9.39            107         0      Not Applicable
  04/19/2026 09 AM PDT            9.39            107         0      Not Applicable
  04/19/2026 10 AM PDT            9.39            107         0      Not Applicable
  04/19/2026 11 AM PDT            9.39            107         0      Not Applicable
  04/19/2026 12 PM PDT            9.39            107         0      Not Applicable
  04/19/2026 01 PM PDT            9.38            106         -      Not Applicable
  04/19/2026 02 PM PDT            9.39            107         +      Not Applicable
  04/19/2026 03 PM PDT            9.39            107         0      Not Applicable
  04/19/2026 04 PM PDT            9.38            106         -      Not Applicable
  04/19/2026 05 PM PDT            9.38            106         0      Not Applicable
  04/19/2026 06 PM PDT            9.37            104         -      Not Applicable
  04/19/2026 07 PM PDT            9.37            104         0      Not Applicable
  04/19/2026 08 PM PDT            9.36            103         -      Not Applicable
  04/19/2026 09 PM PDT            9.36            103         0      Not Applicable
  04/19/2026 10 PM PDT            9.36            103         0      Not Applicable
  04/19/2026 11 PM PDT            9.36            103         0      Not Applicable
  04/20/2026 12 AM PDT            9.36            103         0      Not Applicable
  04/20/2026 01 AM PDT            9.36            103         0      Not Applicable
  04/20/2026 02 AM PDT            9.35            102         -      Not Applicable
  04/20/2026 03 AM PDT            9.35            102         0      Not Applicable
  04/20/2026 04 AM PDT            9.35            102         0      Not Applicable
  04/20/2026 05 AM PDT            9.37            104         +      Not Applicable
  04/20/2026 06 AM PDT            9.38            106         +      Not Applicable
  04/20/2026 07 AM PDT            9.38            106         0      Not Applicable
  04/20/2026 08 AM PDT            9.39            107         +      Not Applicable
  04/20/2026 09 AM PDT            9.42            111         +      Not Applicable
  04/20/2026 10 AM PDT            9.46            117         +      Not Applicable
  04/20/2026 11 AM PDT            9.49            121         +      Not Applicable
  04/20/2026 12 PM PDT            9.55            129         +      Not Applicable
  04/20/2026 01 PM PDT            9.60            137         +      Not Applicable
  04/20/2026 02 PM PDT            9.64            143         +      Not Applicable
  04/20/2026 03 PM PDT            9.67            147         +      Not Applicable
  04/20/2026 04 PM PDT            9.69            150         +      Not Applicable
  04/20/2026 05 PM PDT            9.70            152         +      Not Applicable
  04/20/2026 06 PM PDT            9.71            154         +      Not Applicable
  04/20/2026 07 PM PDT            9.70            152         -      Not Applicable
  04/20/2026 08 PM PDT            9.69            150         -      Not Applicable
  04/20/2026 09 PM PDT            9.68            149         -      Not Applicable
  04/20/2026 10 PM PDT            9.66            146         -      Not Applicable
  04/20/2026 11 PM PDT            9.66            146         0      Not Applicable
  04/21/2026 12 AM PDT            9.65            144         -      Not Applicable
  04/21/2026 01 AM PDT            9.63            141         -      Not Applicable
  04/21/2026 02 AM PDT            9.63            141         0      Not Applicable
  04/21/2026 03 AM PDT            9.62            140         -      Not Applicable
  04/21/2026 04 AM PDT            9.60            137         -      Not Applicable
  04/21/2026 05 AM PDT            9.59            135         -      Not Applicable
  04/21/2026 06 AM PDT            9.61            138         +      Not Applicable
  04/21/2026 07 AM PDT            9.62            140         +      Not Applicable
#
# FORECAST
#
# Date & Time  (Local)    Stage (Feet)     Flow (cfs)     Trend     Forecast Status
# ---------------------------------------------------------------------------------
  04/21/2026 08 AM PDT            9.62            140                Not Applicable
  04/21/2026 09 AM PDT            9.63            141         +      Not Applicable
  04/21/2026 10 AM PDT            9.66            146         +      Not Applicable
  04/21/2026 11 AM PDT            9.72            155         +      Not Applicable
  04/21/2026 12 PM PDT            9.79            166         +      Not Applicable
  04/21/2026 01 PM PDT            9.88            181         +      Not Applicable
  04/21/2026 02 PM PDT            9.96            195         +      Not Applicable
  04/21/2026 03 PM PDT           10.05            211         +      Not Applicable
  04/21/2026 04 PM PDT           10.12            224         +      Not Applicable
  04/21/2026 05 PM PDT           10.18            235         +      Not Applicable
  04/21/2026 06 PM PDT           10.20            239         +      Not Applicable
  04/21/2026 07 PM PDT           10.21            241         +      Not Applicable
  04/21/2026 08 PM PDT           10.22            243         +      Not Applicable
  04/21/2026 09 PM PDT           10.22            243         0      Not Applicable
  04/21/2026 10 PM PDT           10.21            241         -      Not Applicable
  04/21/2026 11 PM PDT           10.20            239         -      Not Applicable
  04/22/2026 12 AM PDT           10.18            235         -      Not Applicable
  04/22/2026 01 AM PDT           10.16            231         -      Not Applicable
  04/22/2026 02 AM PDT           10.14            227         -      Not Applicable
  04/22/2026 03 AM PDT           10.12            224         -      Not Applicable
  04/22/2026 04 AM PDT           10.11            222         -      Not Applicable
  04/22/2026 05 AM PDT           10.10            220         -      Not Applicable
  04/22/2026 06 AM PDT           10.10            220         0      Not Applicable
  04/22/2026 07 AM PDT           10.10            220         0      Not Applicable
  04/22/2026 08 AM PDT           10.10            220         0      Not Applicable
  04/22/2026 09 AM PDT           10.07            215         -      Not Applicable
  04/22/2026 10 AM PDT           10.01            204         -      Not Applicable
  04/22/2026 11 AM PDT            9.94            192         -      Not Applicable
  04/22/2026 12 PM PDT            9.89            183         -      Not Applicable
  04/22/2026 01 PM PDT            9.87            180         -      Not Applicable
  04/22/2026 02 PM PDT            9.86            178         -      Not Applicable
  04/22/2026 03 PM PDT            9.86            178         0      Not Applicable
  04/22/2026 04 PM PDT            9.86            178         0      Not Applicable
  04/22/2026 05 PM PDT            9.86            178         0      Not Applicable
  04/22/2026 06 PM PDT            9.86            178         0      Not Applicable
  04/22/2026 07 PM PDT            9.86            178         0      Not Applicable
  04/22/2026 08 PM PDT            9.85            176         -      Not Applicable
  04/22/2026 09 PM PDT            9.85            176         0      Not Applicable
  04/22/2026 10 PM PDT            9.85            176         0      Not Applicable
  04/22/2026 11 PM PDT            9.84            175         -      Not Applicable
  04/23/2026 12 AM PDT            9.84            175         0      Not Applicable
  04/23/2026 01 AM PDT            9.83            173         -      Not Applicable
  04/23/2026 02 AM PDT            9.83            173         0      Not Applicable
  04/23/2026 03 AM PDT            9.82            171         -      Not Applicable
  04/23/2026 04 AM PDT            9.81            170         -      Not Applicable
  04/23/2026 05 AM PDT            9.81            170         0      Not Applicable
  04/23/2026 06 AM PDT            9.80            168         -      Not Applicable
  04/23/2026 07 AM PDT            9.80            168         0      Not Applicable
  04/23/2026 08 AM PDT            9.79            166         -      Not Applicable
  04/23/2026 09 AM PDT            9.78            165         -      Not Applicable
  04/23/2026 10 AM PDT            9.78            165         0      Not Applicable
  04/23/2026 11 AM PDT            9.77            163         -      Not Applicable
  04/23/2026 12 PM PDT            9.77            163         0      Not Applicable
  04/23/2026 01 PM PDT            9.76            162         -      Not Applicable
  04/23/2026 02 PM PDT            9.76            162         0      Not Applicable
  04/23/2026 03 PM PDT            9.75            160         -      Not Applicable
  04/23/2026 04 PM PDT            9.75            160         0      Not Applicable
  04/23/2026 05 PM PDT            9.74            158         -      Not Applicable
  04/23/2026 06 PM PDT            9.74            158         0      Not Applicable
  04/23/2026 07 PM PDT            9.73            157         -      Not Applicable
  04/23/2026 08 PM PDT            9.73            157         0      Not Applicable
  04/23/2026 09 PM PDT            9.72            155         -      Not Applicable
  04/23/2026 10 PM PDT            9.72            155         0      Not Applicable
  04/23/2026 11 PM PDT            9.71            154         -      Not Applicable
  04/24/2026 12 AM PDT            9.71            154         0      Not Applicable
  04/24/2026 01 AM PDT            9.70            152         -      Not Applicable
  04/24/2026 02 AM PDT            9.70            152         0      Not Applicable
  04/24/2026 03 AM PDT            9.70            152         0      Not Applicable
  04/24/2026 04 AM PDT            9.69            150         -      Not Applicable
  04/24/2026 05 AM PDT            9.69            150         0      Not Applicable
  04/24/2026 06 AM PDT            9.68            149         -      Not Applicable
  04/24/2026 07 AM PDT            9.68            149         0      Not Applicable
  04/24/2026 08 AM PDT            9.67            147         -      Not Applicable
  04/24/2026 09 AM PDT            9.67            147         0      Not Applicable
  04/24/2026 10 AM PDT            9.66            146         -      Not Applicable
  04/24/2026 11 AM PDT            9.66            146         0      Not Applicable
  04/24/2026 12 PM PDT            9.65            144         -      Not Applicable
  04/24/2026 01 PM PDT            9.65            144         0      Not Applicable
  04/24/2026 02 PM PDT            9.65            144         0      Not Applicable
  04/24/2026 03 PM PDT            9.64            143         -      Not Applicable
  04/24/2026 04 PM PDT            9.64            143         0      Not Applicable
  04/24/2026 05 PM PDT            9.63            141         -      Not Applicable
  04/24/2026 06 PM PDT            9.63            141         0      Not Applicable
  04/24/2026 07 PM PDT            9.62            140         -      Not Applicable
  04/24/2026 08 PM PDT            9.62            140         0      Not Applicable
  04/24/2026 09 PM PDT            9.62            140         0      Not Applicable
  04/24/2026 10 PM PDT            9.61            138         -      Not Applicable
  04/24/2026 11 PM PDT            9.61            138         0      Not Applicable
  04/25/2026 12 AM PDT            9.61            138         0      Not Applicable
  04/25/2026 01 AM PDT            9.60            137         -      Not Applicable
  04/25/2026 02 AM PDT            9.60            137         0      Not Applicable
  04/25/2026 03 AM PDT            9.59            135         -      Not Applicable
  04/25/2026 04 AM PDT            9.59            135         0      Not Applicable
  04/25/2026 05 AM PDT            9.59            135         0      Not Applicable
  04/25/2026 06 AM PDT            9.58            134         -      Not Applicable
  04/25/2026 07 AM PDT            9.58            134         0      Not Applicable
  04/25/2026 08 AM PDT            9.57            132         -      Not Applicable
  04/25/2026 09 AM PDT            9.57            132         0      Not Applicable
  04/25/2026 10 AM PDT            9.57            132         0      Not Applicable
  04/25/2026 11 AM PDT            9.56            131         -      Not Applicable
  04/25/2026 12 PM PDT            9.56            131         0      Not Applicable
  04/25/2026 01 PM PDT            9.55            129         -      Not Applicable
  04/25/2026 02 PM PDT            9.55            129         0      Not Applicable
  04/25/2026 03 PM PDT            9.55            129         0      Not Applicable
  04/25/2026 04 PM PDT            9.54            128         -      Not Applicable
  04/25/2026 05 PM PDT            9.54            128         0      Not Applicable
  04/25/2026 06 PM PDT            9.54            128         0      Not Applicable
  04/25/2026 07 PM PDT            9.53            126         -      Not Applicable
  04/25/2026 08 PM PDT            9.53            126         0      Not Applicable
  04/25/2026 09 PM PDT            9.53            126         0      Not Applicable
  04/25/2026 10 PM PDT            9.52            125         -      Not Applicable
  04/25/2026 11 PM PDT            9.52            125         0      Not Applicable
  04/26/2026 12 AM PDT            9.52            125         0      Not Applicable
  04/26/2026 01 AM PDT            9.51            124         -      Not Applicable
  04/26/2026 02 AM PDT            9.51            124         0      Not Applicable
  04/26/2026 03 AM PDT            9.51            124         0      Not Applicable
  04/26/2026 04 AM PDT            9.50            122         -      Not Applicable
  04/26/2026 05 AM PDT            9.50            122         0      Not Applicable
#
# NOTE 1: Stages are rounded to the nearest hundredth (.01) of a foot.
# NOTE 2: Flows are rounded to the nearest (1) cfs.
# NOTE 3: Trends are determined using hourly change in unrounded stage and flow.
# NOTE 4: Maximum Values are determined using unrounded stage and flow.