Old browser warning

Site look funky?  Your browser is either Internet Explorer (hit refresh (F5) several times due to a bug in Microsoft's code that we can't work around) or is 10 years old and standards-based layouts and styling confuse it.   Consider updating.  One excellent option is Mozilla Firefox, versions of which are available for Linux, Mac and Windows. Safari 1.0+ and IE 6.0+ are also supported.

Gauge Information

Gauge Description:

This section of the Ashuelot lies above the Surry mountain flood control dam and therefore is a natural flow river.
The USGS gauge is located below this flood control dam 6 miles downstream from the take out, therefore it should only be used as reference since the Army Corps of Engineers could be discharging more or holding back water for flood control. To get a more accurate reading on the flow go to Army Corps of Engineers Ashuelot tabular data and look at the last reading under the "inflow cfs" heading. It is estimated you will need at least 430 cfs for a scratchy run. The usual gage for this section is on an outside staff of an abandoned USGS gage building just upstream on river right of the stone arch bridge entrance to Gilsum gorge. People with good eyesight or a pair of binoculars can read the level from the river left bank.

Gilsum gorge    Surry Lake
visual gauge    Inflow cfs     Interpretation

   ~4.4           ~430            Minimum
   <4.8           ~480            Scratchy
   <5.1           ~560            Low
   <5.4           ~700            Low to medium  
   <5.9           ~900            Medium
   <6.4           ~1200           Medium high    
   >6.4           ~1500           High
Thanks to Will Kranz for the information used to develop this table.

 

Note: As a result of the two hundred-year-flood events in the fall of 2006 and spring of 2007 the riverbed near the gage has changed.The table above appears to no longer be valid. New observations will be posted as they are accumulated.

 

Date/Time        Gilsum Gorge    Surray Lake         Interpretation
                 visual gage     Inflow cfs

6-Apr-08 4PM      ~4.7            785 (FS 10cfs/hr)   Medium

(FR=Falling Rapidly, FS=Falling Slowly, S=Steady, RS=Rising Slowly,
RR=Rising Rapidly)

 

 


Estimated chance (%) of finding the river runnable.

Month............% chance.................comment 

January ............ 0%....frozen. 
February.............0%....frozen
March................20%....Usually frozen. 
April...............70%....Best chance 
May ................25%....Best chance in early May with rain. 
June.................8%
July.................5% 
August...............5%....Just a trickle
September...........10%....Tropical storms and their remains 
October........�....20%
November............35%....Fall rains, dormant trees 
December............30%....River starts freezing about Christmas. 

Be aware this is averaged out over several years. The % chance refers to the probability of finding the river running on any given day. For instance a 5% probability for August means on average you can only expect 1-1/2 days of water. One year there could be 3 days in August with water, other years none. Spring levels are usually higher than fall levels.

Gauge Information

Name Range Difficulty Updated Level
ASHUELOT RIVER NEAR GILSUM, NH
usgs-01157000 430 - 1700 cfs III-IV 00h37m cfs

RangeWater LevelDifficultyComment
430 -1700 cfs barely runnable-high runnable III-IV

Report - Reports of Ashuelot 1. Marlow to Gilsum Gorge and related gauges

Reports give the public a chance to report on river conditions throughout the country as well as log the history of a river.

Reports

When River/Gauge Subject Level Reporter
4y258d22h07m Ashuelot [NH] Gilsum Gorge 5.6' visual Bob Dunn
5y96d22h07m Ashuelot [NH] Surprise Rapid 6.5 Mark Lacroix