Difficulty II-III(IV) at this flow (II-III+(IV) normally)
Length 1 Miles
Gauge WISCONSIN RIVER AT MERRILL, WI
Flow Range 2820 - 12800 CFS
Flow Rate as of: 36 minutes ago ~ 5470 [CFS] ℹ️
Reach Info Last Updated 04/02/2019 12:49 am

River Description


NOTE: Put-in and Take-out have not been placed on the river, but at location to allow more accurate mapping of parking areas for shuttle route.

NOAA Gauge information:
grfw3_hg.png
OR ... for the detail data, Click Here.

In a project starting the week of April 24, 2017, anticipated to be completed by November, the 43-year old wooden penstocks are to be replaced by steel penstocks which will last 80 years. This means that for nearly all of 2017, all flow in the river will be going into the natural channel. Therefore, we have swapped the gauge back to the Merrill gauge (no longer subtracting the capacity of the penstocks and hydro plant) until this work is completed. All indications are that at the end of this work, the plant will resume operation with precisely the same water consumption/capacity. Therefore, we are not removing from this description any references to the penstocks or their capacity (and the adjustments between gauge values and flow-study or recommended flows), only to have to reinstate that info at the end of the year.



Between the Grandfather Dam and the powerhouse lies a full mile of big, wide river with an amazing jumble of rocks and a few good ledges. With adequate water, this is a wild stretch of river which should allow many options of routes and plenty of play possibilities. Various sites list 89-93 feet of drop, however (best that I can tell) that is the available head-height used by the powerhouse, thus includes height of the dam, which we have subtracted to list the available drop of this section.

There is one ledge about 2/3 of the way down which rates the '(IV)' in the description at flows around/above 2000 cfs . At low-to-moderate flows, this reach may be more in the II-III range, but the continuous nature of the rapids, and pushiness (as it heads to higher water levels) should not be taken lightly.

There is a section of the Ice Age Trail on river left which may be used for scouting, and the road parallels the river not far back from that.

The capacity of the penstock and powerplant is reportedly 2,820 cfs, which would seem to indicate flows in excess of that should put water in this reach. I have seen the river at 'fish flow' (summer trickle), and it would appear that (at least parts of) this reach could certainly be boatable with much less water than the full stretch requires for boatability.

A flow study was conducted May 24, 2014. Participants in that flow study suggest that the run might be broken up into three (very roughly equal) sections, which are detailed in the rapids descriptions below.


A very interesting write-up on Wikipedia mentions the Ojibwe name for this stretch was "Konajewun", which translates as "long falls". That Wiki page also gives an accounting of "what was probably the first and only canoe trip down the falls" in 1849 by two Indians in a birch bark canoe! So, present day whitewater canoeists are following a path blazed more than 165 years ago.

 

Rapid Descriptions

Note:

Class - N/A Mile - 0
Rapid Thumbnail Missing
The following is transcription of comments provided by Bryan Foster on 2014-05-26, after his participation in the flow study.
 

Four different levels were used for the flow study. All levels referenced below are "in channel" levels. To translate listings below to their appropriate USGS gauge readings, you would have to add 2820 cfs. (We are now using a 'virtual gauge' which uses that calculation.)

I: Dam to Pool

Class - N/A Mile - 0.01

The first difficulty is getting safely into the river. As flows increase, the current in the put-in eddy near the dam gains strength, making it difficult to get into your boat and then to charge out into the current. The first two rapids can be scouted by walking along the trail on the East side of the river (a section of the Ice Age trail). Just below the first rapid there is a rock outcropping you can walk out onto scout both drops. This may be used as an alternate (though less than ideal) put in.

The first rapids has 2 main lines. The left line is to the right of a large rock. There are a few waves and one rock that pops up just before a large rock at levels below 1800cfs in the channel. The right line is harder to get to, as you need to ferry across a lot of water to get there. You then run the current about 15 feet off the right bank.

The second rapid in this first sequence forms a catch-on-the-fly wave at levels above 1500cfs which increases in strength to 4000cfs, but is still playable. The river splits, with most of the flow going straight into a boulder garden, and a lesser amount heading off to the right. This first section ends in a large pool before the next section begins.

II: Pool to Ledge

Class - N/A Mile - 0.32

After the pool the pace picks up once again. This is generally a read-and-run section, since the path for scouting is far from the river through this stretch. There are a few eddies to hop down the right bank and a few play opportunities at the entrance and by the eddies, but be on the look-out for a few pour overs in this stretch.

The rapid takes a gentle left hand bend then straightens out and the gradient eases as you approach the Main Ledge drop. Scouting from the left is done for various sneak routes and for punching the meaty hole at certain levels. You can also scout from the right bank for a double drop.

Granddad Ledge - Center (Right) Line

Class - III+ Mile - 0.5

There is a "right side" route (center-river at Granddad Ledge) which opens up at mid-range flows. This was run at 1800 cfs, but most likely was also available at 2000 cfs. No scouting was done of this line at 4000 cfs. A large rock in the middle of the landing zone would be of concern for higher levels. See the picture -- the rock could piton and vertically pin a boat.

Granddad Ledge - Main (Left) Line

Class - III+ Mile - 0.5

While not all that tall a ledge, this develops a pretty mean-looking hole at quite a variety of flows, so is definitely worth a scout (and likely a portage). Sneak lines to the left were popular choices during the flow study, with the hole only being punched at 2000 cfs in the channel (when the hole appeared to be flushing best).

Check out the following video, scouting the ledge (no boater in video) at 3600 cfs on the Merrill gauge:
(Note: This was from summer of 2017, while the penstock was being replaced, so all flow was in the river channel.)

III: Below Ledge to Powerhouse

Class - N/A Mile - 0.57
Rapid Thumbnail Missing

Just after the ledge some large wave holes form at 1800+ cfs. There is large rock pour-over just off the left bank, and just to the right of it is where the wave-hole forms. The pour over offers eddy access to this rodeo hole. The gradient eases and most of the water makes its way over to the right bank, as do most boaters. The gradient builds through some waves that offer play spots and a number of eddies down the right shore. One small ledge/pour-over forms in the middle, but is easily missed by following the wave trains down the right side. A short slack-water breaks up the top of Mark Falls from the middle of Mark Falls. The bottom section contains fewer waves and eddies but more holes and pour-overs, so keep you guard up! The holes did not washout from 1500 cfs all the way to 4000 cfs -- things just got bigger. There is one more slackwater before a runout section with most boaters getting back to the left side of the river. This portion ends with boaters ferrying across the outwash from the Powerhouse to the takeout on river-left.

Comments

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bryan foster
|
2 years ago

Here is a video of the main drop at 3600 cfs per merril USGS gauge. https://youtu.be/1jgnOFwzIiQ

Gage Descriptions

Call 715-536-8114 or -7289 weekdays 7am-4pm for flow info.

As part of the relicensing for 2018, WPS proposes they will: "Post river flows, reservoir levels, and bypass reach flows on WPS’ website and update regularly. This includes posting of any planned maintenance projects that would divert flow to the bypass reach".

Gauge/flow analysis (based on USGS data, 1903-2011)

Drainage area at gauge: 2,760 sq.mi.
Minimum daily mean flow (1908.09.26): 90 cfs
90% of time flow exceeds: 1,220 cfs
50% of time flow exceeds: 2,050 cfs
10% of time flow exceeds: 4,330 cfs
Maximum daily mean flow (1941.09.01): 36,400 cfs
10/90 ratio ('flashy-ness'): 3.55 (under 3 is quite steady, over 10 is quite 'flashy')

The above would indicate that somewhat less than half the time (on average) there should be flow in excess of penstock/hydroplant capacity, and thus something more than 'fish flow' (50 cfs) in this bypassed reach. Further, AT LEAST 10% of the time (~36 days per year . . . more than a full month) natural flows should exceed penstock/hydroplant capacity by at least 1,500 cfs, putting that much in this bypassed reach.

Directions Description


NOTE: Put-in and Take-out have not been placed on the river, but at location to allow more accurate mapping of parking areas and for shuttle route.

If you are ambitious/energetic and/or have only one vehicle, it is also possible to just walk the one-mile (parking either at lower or upper access). While the Ice Age Trail runs through here, and is convenient for scouting a fair part of the run, it is not real convenient for a hike with a boat. We would recommend instead following alongside the penstock (at least, when reconstruction is completed in late 2017) and the forebay (canal).

No Accident Reports

Alerts

News

article main photo

Grandfather Falls Licensing About to Get Underway (WI)

12/6/2012
Thomas O'Keefe

The Federal Energy Regulatory Commission (FERC) has recently announced the commencement of relicensing proceedings for the Tomahawk and Grandfather Falls Hydroelectric Projects in Wisconsin. We are pleased to report that FERC has identified whitewater recreation as one of the issues requiring study and analysis and has proposed a whitewater flow study. Paddlers have the opportunity to attend next week's public meeting and file written comments.

article main photo

Midwest Hydro Successes

6/26/2004
Thomas O'Keefe & Angie Tornes

Working in close partnership with AW since the first flow study on the Pine River in 1991, the Rivers and Trails Program has assisted us in obtaining significant benefits for whitewater recreation through the FERC licensing process. Several projects in the midwest have benefitted from this productive partnership.
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Rob

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Matt Muir

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Thomas O'Keefe

Revisions

Revision #Revision DateAuthorComment
1207746 06/20/17 Rob reposition in/out for better shuttle directions & parking/access
1207747 06/20/17 Rob formatting fix
1208793 01/27/18 Rob minor edit
1211681 04/02/19 Rob updated image position
1192656 03/25/09 n/a n/a
1201508 07/26/12 Rob Add gauge analysis.
1196707 11/23/09 Rob Fix/remove broken links.
1203578 07/25/14 Thomas O'Keefe photo change
1204342 03/15/15 Rob incorporate flow comments into rapids detail
1206411 05/07/16 Rob refine/remove ancient flow info
1207518 05/08/17 Rob news re: penstock replacement
1207564 05/18/17 Rob embed NOAA gauge at GFF