Mongaup River

Rio Powerhouse to Delaware River(Rio Reach)

Reach banner
DifficultyII+(III)
Length3 mi
Avg Gradient53 fpm
GaugeMongaup River Near Mongaup Ny
Flow Rate as of 50 minutes
185 cfsbelow recommended
Reach Info Last UpdatedJune 8, 2025

River Description

This regional gem has regularly scheduled recreational releases, and frequent power releases from Rio Dam. For the release schedule, see Eagle Creek's Release Schedule.

Releases are 1 tube or barrel (about 500 cfs) and 2 tube (~1000 cfs).  1 tube requires more maneuvering but has less push making it easier for the less experienced. 2 covers a lot more of the rocks but gives holes and drops more power.  According to an Eagle Creek employee, standard 2 tube policy is to start 1 tube at 10 a.m. and leave 1 tube running till 4 p.m.

As you'd expect with paddlers, opinions vary as to which is best or even easiest.

Unscheduled Releases

Power releases occur frequently on the Rio Reach.

As of June 2020, Eagle Creek, the dam operators, started posting a day or 2 ahead generation forecast at Rio on the Mongaup at  https://www.eaglecreekre.com/facilities/operating-facilities/mongaup-river-hydroelectric-system/mongaup-river-system-lake-levels-and-rio-operation-forecast.

During extremely wet years all the upstream reseviors get filled and flows get much higher. Around 2k water starts to flow thru trees with force, greatly increasing the consequences of swims.

The only guidebook description is in Dennis Squires' 'New York Exposed: The Whitewater State, Volume 2,', which (on p 140) describes the rapids as 'pretty continuous class II and easy class III all the way down to the Delaware.'   In general terms, while the gradient is fairly consistent on this reach, the rapids on the second half of the reach (below the lunch spot) are more sustained than on the upper portion. Save some energy for the rapids under t

...

River Features

Upper section

Distance: -1 mi
Other
Upper section

Above the dam runs only with quite a bit of rain or if the power company diverts water.
At 750cfs over the dam in April, 2026, this was a beautiful class 2 with some play and little wood.
i'd guess somewhere around 400 and up is good (each turbine adds about 440cfs to the flow. Do the math).

In October 2019 AW ran a test of releasing 250csf from the dam to see if that would fit into the re-licensing plan. Something like 30-40 paddlers showed up to participate and report back if that amount of water would be worth releasing. The answer was no, but a bit more water and some cellulose extraction would make this a nice training run and the overall run longer.

Put In - Rio Powerhouse

Distance: 0 mi
Access Point
Put In - Rio Powerhouse

Limited parking for popular release days so park nice and did we mention drive really slow on the dirt road.

Usually there's a porta potty paid for by the dam operators.

Powerhouse wave

Class: IIDistance: 0 mi
Playspot
Powerhouse wave

Not a bad surfing wave at 2 barrels but pretty sticky and shallow at 1. Don't be embarrassed by the crowds...give it a try.

Somewhat challenging to get in. Tons of room to roll up.

Cliffs

Class: IIDistance: 0.1 mi
Other
Cliffs

Starting at the end of the pool below the powerhouse, a slight left turn pushes most of the river's volume against low cliffs on river right. Easiest route is center to way right into a huge eddy above the cliffs then right to left into an even huger eddy on left. Some prefer a left line through the waves but with that much water pushing against the cliffs you've got a set a fairly hard ferry angle in waves....beginners should  stay off the cliffs.

Long boat challenge (while you wait for everyone)- attain to the first big eddy on river left.

Small boat challenge - Hit the eddy's under the cliff. There's at least 3.

Don't go right

Class: IIDistance: 0.44 mi
Rapid

After some boogie water, river takes a slight right turn with most of the water and paddlers going left. Beginners may find right looks tempting with less flow and reasonable lines. But lots of rocks, guard rocks...best to stay to left of large mid river rocks. Especially fun is an inviting looking boof rock at 2 barrels. Left side is ok: right has a rock below the surface that knocks you sideways, possible pinning (not enough water to be dangerous), usually spinning...Just go left, ok.

Canoe Lunch Spot

Class: IDistance: 1.3 mi (approx.)
Access Point
Canoe Lunch Spot

On river left. Not sure why they stop here but they do.

Boof Rock Lunch Spot

Class: II+Distance: 1.4 mi
Playspot
Boof Rock Lunch Spot

2nd significant drop. River goes left over some low ledges and then drops right and pushes against  low cliffs as it ends in a pool. At the right of the flow at is a protruding boof rock. With 2 barrels aim to hit straight on. Too far right lands you on rocks (at 1 barrel you scrape over).

Easiest line thru the rapids is just left of the boof rock (and right of the main flow) so you don't get pushed up against cliffs.

After the rapids great squirt lines off cliffs. Nice beach at right popular for a short break (and  squirting or attaining can entertain those who don't like to stop).

Island Rapid

Class: II+Distance: 1.5 mi
Other
Island Rapid

Below the pool is an island with most water going right. At 1 barrel you have no choice. At 2 you can go left for a sneak that is a lot like most of the Mongaup at 1 barrel.

Far right side catches wood.

Lower Rapid

Class: II+Distance: 2.1 mi
Other
Lower Rapid

This is the meat of the Mongaup... a fairly continuous 3/4 mile with drops of up to several feet. Fun for experienced paddlers. Very few large eddies. As you'd expect inside of bend is usually a little easier but the entire rapid is gradual enough that an experienced paddler can read and run and choose the smoother lines. For the beginner though things happen pretty quickly and if your not looking very far ahead...

Starts with

Casa Bonita...

where most boaters fly right through that has a ton of play for the adventurours.... hit all of the super fun

Makeout Takeout (Upper)

Distance: 2.9 mi
Access Point
Makeout Takeout (Upper)

Actually a nice takeout on right above bridge. Sign has been edited. Carry up a steep bank and there's parking for half a dozen vehicles right there.

Bridge waves rapid can be challenging for a beginner and if the Delaware is high boat and swimmer recovery is a pain as you can easily get carried well below any of the pullouts.

Takeout on the Delaware (Upstream)

Distance: 2.96 mi (approx.)
Access Point
Takeout on the Delaware (Upstream)

The upstream takeout is at Zone 18 520250E 4585885N. It has an NPS sign, and is designed for the convenience of the many rafters on the Upper Delaware. It does, however, lead to the NYS DEC parking area, where most of us park.

Bridge Rapid

Class: II+Distance: 3 mi
Hazard
Rapid
Bridge Rapid

Cobbly drop with some play at top ending in a high speed wavy chute that is a bad place to be upside down, so those without a bomber brace should get out before the bridge at the make out take out. Even at 2 barrels it's not the final chute is too shallow for a proper set up and roll and upside down paddlers are moving quite fast. Experienced paddlers with a solid brace will have no issues, but those who have struggled further up are better avoiding this rapid. At 1 barrel about 100 feet below the bridge a little left of center is pointy flake that will launch you. Unless you've scouted carefully don't go to close to the island near the bottom as it catches wood. After the island head right and up the Delaware.

Bridge Rapid

Class: IIDistance: 3 mi
Other
Bridge Rapid

Under the route 97 bridge and into the Delaware. Big waves. Some claim it's the hardest rapid, but it's really just big waves, though  there's some rocks not far under the surface in the main flow.

BEGINNERS WITH A SHAKY BRACE might be well advised to exit above the bridge as flipping bounces you off rocks at speed. (Note it's gotten worse in 2022 or so and will probably change again).

Also if the Delaware is flowing boat recovery is a real pain so....

There's a nice pull out on river right....up a steep embankment but then a much shorter carry. If the Delaware is really flowing this is a nice alternative period.

Some play at 1 barrel...at 2 it's pretty much a flush.

Exit river right and paddle up the Delaware to pull outs on river right.

Takeout on the Delaware (Downstream)

Distance: 3.3 mi (approx.)
Access Point
Takeout on the Delaware (Downstream)

On the Delaware, the downstream take out is at the confluence on the east side, at about Zone 18 520493E 4586022N.

Beach Takeout

Distance: 3.4 mi (approx.)
Access Point
Beach Takeout

This is the same as the takeout for the Mongaup Wave on the Delaware.


JP
Joshua Poston

Aug 8, 2013


The under bridge construction at the Route 97 rapid appears to be completed.

JP
Joshua Poston

Jun 20, 2013


All of the websites and numbers have been updated. Safe Paddling Everyone.

CK
Cameron Klinger

Sep 11, 2011


If you have natural flow, you can put in below the Dam. This section down to the release put-in is similar in difficulty to the normal release section.

LC
Lauren Cook

Apr 11, 2008


Releases will commence, for the first time in nearly 3 years, on April 19!

Tom Hart
Tom Hart

Jan 1, 1900


DanO nailing the boof.

SK
Sean Kraft

Jan 1, 1900


Penstock

LC
Lauren Cook

Jan 1, 1900


Paddlers negotiate the rapid under the Route 97 Bridge.