Pemigewasset - 5) Ayers Island Dam (Bristol) to Coolidge

Pemigewasset, New Hampshire, US


5) Ayers Island Dam (Bristol) to Coolidge (Bristol Gorge)

Usual Difficulty II(III) (for normal flows)
Length 1.6 Miles
Avg. Gradient 25 fpm
Max Gradient 35 fpm

Jason at the Pemi Play Hole

Jason at the Pemi Play Hole
Photo of Jason by Matt Allison @ 800 cfs

Gauge Information

Name Range Difficulty Updated Level
usgs-01076500 400 - 12000 cfs II(III) 00h21m 1660 cfs (running)
Usual release level. Good play, fluid, not too shallow.

River Description

River description.
There is a small parking area at the put-in near Ayers Island dam. There is a porta poty located here along with trash cans. Additional parking can be found at the top of the dam where a hiking trail leads down to the put-in parking lot.
The river is about 1-1/2 miles long with three distinct play spots. The first big drop is about 1/4 mile downstream with a medium size sidesurfing hole (Rodeo Hole)it is not for novices to play in. Run right at this point. Downstream 100 yards there is a good surfing wave depending on level. The river from this point to the take out is mostly small rapids with a few oppertunities for surfing a sidesurfing. The last rapid is a series of reactionary waves and holes caused by protruding ledges on a long sweeping right turn. The last ledge at the take out is probably one of the best summer time play spots in NH with a great sunning and spectating rock to go with it. Depending on level it is either a sidesurfing hole, surfing wave, and or ender spot.
You can takeout at the Pemi Park & Play or just slightly downstream at a ledge. This take-out is easier for canoes and rafts. It also leads up to a small parking area on Coolidge Woods road which has new porta poties maintained by Public Service company of NH.

Technical info

Put in elevation........370'
Take out elevation......331'
Total drop..............39'
Average drop/mile.......25'
Distance................1.6 miles
River width average.....120'
River geology...........small boulders and granite ledge
River water quality.....fair to good, clarity fair, sewage treatment dumps in
                        below rodeo wave.
Scenery.................Good forest scenery.  Not many signs of civilization
                        except for dam and bridge.
Wildlife................Occasional deer, hawks, osprey, fishermen.  Good trout 

Mapquest Directions

From Concord, NH 


Directions from southern NH.

Interstate 93 north to exit 23.
Left on state rt. 104 (west) towards Bristol.
Approximately 4.5 miles, look for a baseball field on the left.
There will be a yellow playground sign just before you get there.
Take a left here and go around the ball field towards the recycling
Drive past the entrance to the town garage, sewage treatment
facility, and recycling center. The road at this point turns to a
rough dirt road descending steeply to the small parking area at the
base of the dam. Note new handicap accessible outhouse.

Directions to the take out:
As of the Fall of 2009 a new bridge opened to replace the metal truss bridge that used to cross the river from Bristol to New Hampton.  This cuts the shuttle down to 2 miles from the 8 miles we had to endure over the last couple years.

Head back out to NH rt 104 and take a left toward Bristol.

In the center of town at the intersection of rt 3a take a left then another immediate left in the town square.

Take the right (downhill) at the fork. 

Follow the road down over the bridge then take a right on Coolidge Woods road (dirt).

Approximately 1/3 mile to take out. Look for vehicles parked at the
play spot. Or take out a little further down stream where the river
flattens out. 


New put in access

In the summer of 2006 a new river access path was put in by PSNH. It is accessed from the same parking area. The path leads a short distance downstream from the old put in. The path is made up of crushed stone and has an even grade all the way to river level. This is a great improvement over the continually shifting rock jumble we used to put in at.

Osprey Webcam

In 2003 Public Service Company of New Hampshire installed an artificial osprey nest at their Ayers Island hydro facility. Since that time a nesting pair of Ospreys have taken up residents to raise their chicks for the last few years. This Nest is visable from the putin. Look to the river left side of the dam to view the telephone pole platform with a large nest on top. In the summer of 2006 PSNH installed a webcam so we can view the nest at anytime.


Flow Info:

This entire section is regulated by Ayers island hydro dam at the put-in. The USGS gauge referred to above is located upstream of the dam in Plymouth NH. When this gauge exceeds 1300cfs, water is just about guaranteed in Bristol. Water is available at other times when this guage is below 1300cfs but Ayers Island Hydro regulates releases below the dam. This is a peaking power station so levels sometimes rise and fall without warning. To get the latest best guess level information call after 7pm the day before (603) 634-3569 for a recorded phone message. You can call the dispatcher for specific info 603-669-4000.
To find out if the Pemi has been releasing recently go to the Army Corps of Engineers Franklin Falls flood control dam webpage and look at the last reading under the "inflow cfs" heading. Unfortunately there is a several hour delay between the release at Ayers Island and the reading on this webpage. Use it only to get a recent release history.

There are four Summer releases of at least 900 cfs that were negotiated during dam relicencing a few years ago. Usually one weekend in July and another weekend in August.
400 cfs ......minimum scratchy level
600 cfs.......very low
800 cfs.......low
1100 cfs......low to medium
1500 cfs......medium
2000 cfs......medium high
2700 cfs......high
3400 cfs......very high
>6800 cfs.....Pemibec


2011 Pemigewasset Bristol releases (Ayers Island dam)




Sat. July 9th 10:00am to 3:00 pm 1000 cfs AMC instruction
Sun. July 10th 10:00am to 3:00 pm 1000 cfs if water is available
Sat. Aug. 20th (to be confirmaed) 10:00am to 3:00 pm 1000 cfs MVP Release
Sun. Aug. 21st (to be confirmed) 10:00am to 3:00 pm 1000 cfs if water is available

Note: The 20th annual and last MVP Pig roast was held in August of 2008.  The Brunning farm has been sold so there is no longer an open invitation to camp at the farm as we have been able for the last quarter century.



StreamTeam Status: Not Verified
Last Updated: 2018-05-02 13:11:05


Rapid Summary

Mile Rapid Name Class Features (Legend)
0.0Map of the Lower Pemi regionPutin Takeout Photo
0.3Rodeo HoleII+Playspot
0.4Rodeo WaveIIPlayspot Photo
1.3Coolidge RunII
1.5Pemi Park & PlayIITakeout Playspot Photo

Rapid Descriptions

Map of the Lower Pemi region

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Rivers of the lower Pemigewasset region

Rivers of the lower Pemigewasset region
Photo by Mark Lacroix

Wourthen's (Class II+, Mile 0.3)

The first big drop is about 1/4 mile downstream with a medium size sidesurfing hole (Rodeo Hole)it is not for novices to play in. Run right at this point. After the first few small class I-II rapids from the put-in, the river widens and slows down. You will notice a ledge protruding from the left bank (Wourthen's Rock) forcing the river to the right. Get out and scout on these ledges or run to the far right to avoid "Rodeo Hole". The rapid continues for about 1/5 of a mile with waves and turbulance and a few rocks to avoid. Just downstream from the middle of the rapid you will notice the river takes a slight jog to the left between another set of ledges, eddy out river left below the ledges to catch a nice surfing wave.

Rodeo Hole (Class II+, Mile 0.3)

Nice sidesurfing hole located at the very top of Bruning's. Approach the top of Bruning's at the horizon line about river center. The hole turns into a surfing wave just right of river center. There is no convienient eddy to hop in and out of the hole so it will be necessary to catch it on the fly then return by carrying back over the ledges from the river left eddy just slightly downstream. The hole is best at about 1300 cfs, below this level down to 800 cfs the hole gets stickier and shallower so watch your head should you flip upstream. There is also a nice surfing wave that can be accessed from an eddy just downstream. It is best at 800 cfs to 1500 cfs.

Rodeo Wave (Class II, Mile 0.4)

Joe surfing at Brunning's

Joe surfing at Brunning's
Photo of Joe Damboise by Mark Lacroix taken 06/02/02 @ 1600 cfs

Nice surfing wave at the end of Bruning's. Catch the eddy on river left just below the ledge. The wave is best at 1500 cfs flattens out and gets more difficult to catch down to 900 cfs.

Coolidge Run (Class II, Mile 1.3)

The last rapid is a series of reactionary waves and holes caused by protruding ledges on a long sweeping right turn. The last ledge at the take out is probably one of the best summer time play spots in NH with a great sunning and spectating rock to go with it.

Pemi Park & Play (Class II, Mile 1.5)

Katrina at the Pemi Park & Play

Katrina at the Pemi Park & Play
Photo of Katrina Santos by Matt Allison @ 800 cfs

One of the best summer play spots in New England. Located at the end of Coolidge Run, the river piles up against a ledge then funnels into slack water below causing a series of waves at higher levels and a surfing hole at low levels. Typical summer time low levels of 300 cfs to 500 cfs provide a nice hole for surfing, side surfing, and many of the new play boat manuevers. Above 900 cfs the hole turns more into a wave. At 1500 cfs there is a nice wavetrain the forms with the best surfing at the top. Enders up against the rock are best at 800 to 1200 cfs.

User Comments

Users can submit comments.
May 18 2009 (3469 days ago)
Paul CooperDetails
With the bridge out; it is not too difficult to leave a vehicle at the take-out then walk/boat to
the putin. Most people know there is a very nice path on the New Hampton (paddler's left) side of
the river that makes it easy to drag or carry a (light) boat from the bridge to the first drop. If
you ferry across the river from there you can take back out at a small pebble beach just before the
first drop on the right side of the river. From there go about 20 feet uphill and you will
magically appear on a lawn that appears to be maintained by Public Works. You will see a fence that
makes it look like you are behind a locked gate but before you get to the fence you will be on the
road near the recycle center. It appeared to be pedestrian friendly and I did not see any posted
no-trespassing signs but it would be prudent to show the area the full respect one would show any
private property just in case.
You can scout this on your way to the putin also. When you get to the recycle center take a right
instead of the left you usually take then the field will be on your immediate left. You can drive
half way down the field on the roadway then take the short walk to the river. As with any outdoor
area take precautions against natural hazards such as ivy, ticks, etc.

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