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RiverBrain

Colorado – US

Class
V to V+
Length
5 Mile(s)
Gradient
140 FPM
Put-in elevation
6,866 Feet
Take-out elevation
5,941 Feet
Typical season
April to July
Author
KSC

Current Flow

63 CFS

Reading from Jul 10, 2026 10:30 PM

-0.36/hr (12h) -0.18/hr (24h)

Too Low

Don't bother

Primary gauge
[SAINT VRAIN CREEK AT LYONS, CO]-[NORTH SAINT VRAIN CREEK BELOW BUTTONROCK]+25 Gauge detail & alternatives
Flow formula
[SAINT VRAIN CREEK AT LYONS, CO]-[NORTH SAINT VRAIN CREEK BELOW BUTTONROCK]+25 computes to 63.9 right now
Alternative gauge
[SAINT VRAIN CREEK AT LYONS, CO]-[NORTH SAINT VRAIN CREEK BELOW BUTTONROCK]-25 13 CFS

Recommended levels

Minimum200
Average275
Maximum400

Recommended use

  • Kayaking
  • Rafting
  • Canoeing
  • SUP
  • Packrafting
  • Fishing

Struck-through craft are not recommended for this run.

Flow history — last 6 days

Photos

Overhanging Rock Rapid · 05-18-2013 · Fun in the mank · Photo by Kevin Cripps · Subject: Lucas Spaulding

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Description

READ THIS FIRST: SSV was heavily impacted by the Colorado floods of 2013.  The entire riverbed was rearranged in many sections. The banks are very unstable in some sections, and rapids are expected to shift as the water levels come back up.  Scout carefully and often!  2016 update: Most people are running the section from the narrows through 1 in 5 as it's currently the cleanest and least hazard free.  The main section as it's described in the Rapids section has been largely damaged and is full of hazards and marginal lines.

 

SSV is one of the Front Range's classic creeking training runs.  Known for its mank and nonstop action, it brings a smile to those who love the bar room brawl feel of the run, and disdain for those who get tired of hitting rocks and taking backstrokes.  Unless the flows are unusually high, this is a good run to bring your mank boat, if you have one.  The normal afterwork run starts just downstream of a large pullout with a small restroom facility.  If flows and time allow it, putting in at the confluence of the middle and south forks offers a longer run.  The entire run is roadside and scouting is trivial.

Once you become familiar with the lines, the run is not terribly difficult, yet clean runs tend to be rare.  The continuous steep character and low volume punish upside boaters.  Holes are rarely a problem, but a few sticky ledge holes will dish out some rides and occasionally swims.  A running joke in our crew, is that on the scout, lines on SSV look terrible as you analyze every rock in your path.  Yet, somehow, the lines magically run relatively smoothly.

There is no active gauge on the South Saint Vrain, so flow must be calculated from other gauges.  The flow on this run is calculated by subtracting the NSV flow from the flow in Lyons below the confluence.  The NSV flow is calculated differently depending on whether Buttonrock Reservoir is full or not.  The primary and secondary gauges reflect the different measurements:

Primary Gauge: When Buttonrock is spilling, the NSV branch will contain the reading on the gauge above Buttonrock plus 25 cfs that Longmont pulls consistently from Longmont reservoir.  Using the gauge below Buttonrock does not account for the spill that enters back into the creek below the gauge.

Secondary Gauge: When Buttonrock is not spilling, the NSV branch will contain the reading on the gauge below Buttonrock minus 25 cfs that Longmont pulls consistently from Longmont reservoir.

 

A foot gauge (visual only) is located on SSV in Lyons and provides a fairly accurate measurement of the flow on this run proper.  There is a Facebook page called "South Saint Vrain SSV Gauge" where the community posts updates on the gauge level.  To reach the foot gauge from the intersection of 4th Ave and Prospect in Lyons (Prospect is the last street on the left in town as you begin to drive up the canyon), go south to the end of 4th Ave.  Walk across the bridge.  The gauge is located on the upstream side. If none of the above data is available, to estimate the flow in SSV, the upper gauges can be used, but more water will be in the actual run. 

The flow apex is around 2am and the nadir 2-3pm

 

Gauge links:

St Vrain at Lyons: https://www.dwr.state.co.us/SurfaceWater/data/detail_graph.aspx?ID=SVCLYOCO&MTYPE=DISCHRG

North St Vrain below Buttonrock: http://www.dwr.state.co.us/SurfaceWater/data/detail_graph.aspx?ID=NSVBBRCO

Rapids

# Rapid Class Recommended flow Description Scout
1 Confluence Rapid V- —–—

This is a long stair stepping rapid just below the confluence of the middle and south branches that gets the blood flowing quickly.  Scout the line carefully to avoid the mank, but it usually goes better than it looks, much like all the drops on SSV.

2 Intro Slide V- —–—

Just below the confluence rapid comes a fun slide.  Just point your boat straight and try to exit on the right side.

3 Broken Knee V —–—

After a long stretch of boogie water from the confluence put-in, there is a large slow moving pool.  This is also the put-in for the shorter, classic SSV put-in.  This rapid starts below the pool.  Navigate a couple small entrance holes, dodge the mank, and set yourself up to drive center and right for the last flume.  This rapid usually goes smoothly but carnage can be epic.  See the accident report for how this rapid got its name.

4 Double Drop V- —–—

This rapid is a straightforward double drop with a nice ledge boof on top into a large eddy.  The second tier requires a left to right move to avoid the mank at the bottom.

5 Sign Post V- —–—

The rapid's name is derived from a sign post that used to be present in the rapid.  The rapid starts on river right and feeds into a 4 foot ledge against a river right cliff wall.  The river makes a dramatic turn to the left, which often spins unsuspecting boaters backwards and into a small but sticky ledge hole on river left.  Be heads up because this rapid feeds directly into the next.

6 Bed Springs V —–—

Scout this rapid carefully before committing.  The standard line is to catch a small bleeding eddy on river left just above the crux and ferry above a deadly looking pile of pin rocks to the river right eddy, which provides a safe passage below.  Many people choose to walk this rapid.

7 Overhanging Rock V- —–—

This rapid's namesake is derived from the promiment overhanging boulder on the right shore midway through the rapid.  Navigate the mank pile up top and catch the river right eddy above the squeeze between two b oulders.  At lower flows, thread your way another 10 yards downstream and catch the eddy on river left.  This eddy provides a perfect setup to squeeze between a rooster tail and the overhanging rock.  Hit the slide below it with left to right momentum in order to avoid a piton at the bottom.  A few more manky ledges below will deliver you to more manky boogie water.

8 Triple Drop V- —–—

Many consider this one of the most fun rapids on the river.  Punch a hole down the middle, then stay straight through a hole with a diagonal wave reflecting off the right wall.  There's a decent sized eddy on river right after the second hole to set up for the final drop.  The final drop requires slaloming through some mank on the left side and then driving toward the center for broken ledge drop that terminates in a small, but sticky hole.

9 Narrows - Entrance Drop V+ —–—

This is one of the most consequential rapids on the run.  The entrance is a steep ramp into a hole followed by a constriction with a rock in the center that forces the boater to chose the left or right side.  Left is usually preferred if you can make it, as it avoids the danger of having your paddle chalk against the cliff wall.

10 Narrows - Rock Jumble V —–—

After the narrows entrance, a steep section of jumbled roadside rock blast awaits.  If you are not upright and in control at this point, bad things await.  Like much of the run, this section tends to go better than it looks, but a random piton is not out of the ordinary here.

11 Narrows - Double Drop V- —–—

After the ugliest and steepest part of the Narrows comes this nice double drop.  The first drop offers one of the best boofs on the run.  Hit the hump on the side and punch through the second hole.

12 Narrows - Wall and Clamshell Boofs V- —–—

The flow constrictions against the right cliff wall and drops over a 5-6 foot ledge. Crank a glorious boof over this ledge, stay right (unless you're racing) and boof the left edge of the clamshell hump at the next horizon line to avoid a rock in the landing zone.

13 Narrows - Jihad V —–—

The last rapid is ugly and rarely sees a clean run, although it is possible.  Fortunately it's also generally relatively forgiving, which is to say after you piton, flip and drag yourself over the bottom boulder, you can roll up below and try to piece together what just happened to you.

14 One in Five V- —–—

The obvious last rapid on the run that can be seen from the highway.  We've done some experimentation, and the odds are actually much better than the name would suggest.

Access

Type Name Elevation Camping Water Boat ramp Vehicle access Description
Put-In Confluence Put In 6,866 Feet No No No All Vehicles

Where the upper and middle forks of the South fork of the Saint Vrain meet on CO Highway 7 east of Lyons, CO is a pull off that can be used to put in for the SSV.

Take-Out SSV Take Out 5,941 Feet No No No All Vehicles

About 5 miles below the putin is another pull off/picnic area you can use as the take out for SSV.  This is also where Central Gulch joins the Saint Vrain Creek.

Camps

No river camps added yet.

Permit

No permit is required, or permit info hasn't been added yet.

Fishing

No fish species have been associated with this run yet.

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