Saru River (Iwachishi to Horokeshi)

沙流川 | Sar

Posted on Jun 13, 2023

Posted on Jun 13, 2023

0 0


0.5 day(s)


6.3 mpk



Water clarity

Class III



Best season





The Saru River 沙流川 from below the Iwachishi Dam hydro outlet 岩知志ダム放水口 to Horokeshi-bashi bridge 幌毛志橋, just above the Nibutani Dam, is a 12km fast-moving run dotted with rapids. A few of the rapids can have large wave trains on their exits with the right water levels. This is a popular alternative Saru River section when the steeper, more constricted upper sections are a bit too sporty for one's liking. Similarly, while other sections of the Saru can suffer from low water in the summer months, this section tends to have a better flow thoughout the season. It's possible to put in further up the river near the hydro outlet, but there are two portage-able weirs to contend with.

We visited this route on Sep 4, 2021

Paddlers: Haidee, Mari and Greg, Taku. Many thanks to Greg for water level notes for this section.


Route Map

Need to know details

Grade: III
Engagement: E1
Remoteness: 1/5

River Details

This route is on Saru River (沙流川), or Sar in the Ainu indigenous language. The river is a Class A (一級河川) river, 135km in total length. This section of the river is between 10m and 30m wide. The gradient for this section of river is 6.3 mpk (33.26 FPM).

Weather: weather forecast for Saru River

Ideal water level: 57.20m
Water level paddled 57.04m

The Saru River flows southwest from high up on the western side of the northern reaches of the Hidaka Range, in southern-central Hokkaido. This section of the river starts about 4km downstream (south) of the Iwachishi hydroelectric dam outlet.

Put-in Location: Google Maps

Most paddlers put in about 4km downstream of the Iwachishi hydroelectric power station, just after the small weir, here. There’s a gravel road down to the stopbank, and it’s an easy 50m carry from there to the riverside. Putting in here means there are no portages required for the entirety of the 12km paddle downstream.

Alternatively, it is possible to put in about 4km upstream at the Iwachichi hydroelectric station. It’s a bit of a scramble, but paddlers can climb down to the river at the northern end of the concrete embankment, around here. The scramble is unlikely to suit paddlers with 16ft open-deck canoes, as you’d likely need to lower the canoes down the concrete wall using ropes first. If paddling packrafts or smaller kayaks, it will be less terrible. Note that putting in at the hydro station will mean there will be two weirs to navigate – both are runnable at the right water levels, but are also able to be portaged (both on the river right). Definitely scout before considering running them.

Take-out Location: Google Maps

The lowest take-out point before Nibutani Dam にぶたにダム is at Horokeshi-bashi Bridge 幌毛志橋, here. Horokeshi-bashi Bridge is about 6km upstream of where the Saru River flows into the lake. On river left, there’s an access road to a large gravel area under Horokeshi bridge. Alternatively, it’s possible to take out upstream of Horokeshi Bridge, 4km upstream in Furenai, here. We’ve also seen references to paddlers taking out at the headwaters of Nibutani Lake at the Nibutani Dam Kanri Bridge 二風谷ダム管理橋, but don’t currently have beta on exactly where paddlers take out there.

General notes

This lower section of the Saru River doesn’t see as much paddling action as the more picturesque upper sections (such as the Hidaka to Mitsuiwa gorge section). In the right water level conditions, however, this lower section can be a heck of a paddle, with some very big water in places. Overall, in fact, the gradient of this lower section of the river is steeper than the gorge section further upstream. Rapids are very well spaced apart however, so if you do happen to capsize, self-rescue will be less stressful. Furthermore, while the rapids can be pushy, in general the river is wider than upstream, allowing for easier scouting.

Route description

Put in just downstream of the weir, and enjoy about 600m of easy swifts before the first pushy CII+ rapid of the trip. Then it’s another 1km or so to another CII+ rapid just before Horosaru-bashi Bridge 幌去橋. Another 1.2km downstream is a 100m long CII+ rapid that is easily scouted from the road above – we’d recommend scouting this in advance if possible. Another 1.8km downstream is a small CII rapid/wavetrain, just downstream of Furenai-bashi Bridge 振内橋. Arguably the crux of this section is the CIII rapid/slider about 600m downstream of Ikeuri-bashi Bridge 池売橋. We’ve heard of people cracking boats on just-submerged rocks (or maybe concrete tetra-blocks?) on this rapid. Best considered a must-scout – there’s easy access to the riverside river left above the rapid. The rapid may also be pushing somewhat to the river right, into the concrete blocks on the outside of the bend. It’s possible to take out at this point.

The remainder of the paddle to Horokeshi-bashi Bridge 幌毛志橋 is fairly straightforward. There’s a low weir runnable on the river left, and beyond that, just a few swifts for the remaining 4km to Horokeshi-bashi Bridge.

Route Timing
Trip time: 4hrs 0min


Public transport:

There’s a Donan Bus company bus that runs along Route 237 alongside the river for the entirety of this run, making access via public transport fairly easy. For the put-in, there’s Iwachishi Bus Stop 岩知志バス停, about a 700m walk to Heiwa-bashi Bridge 平和橋. Cross the bridge and walk 100m upstream to where you can access the river through the bush. For the take out at Horokeshi-bashi Bridge, there’s the Shinhorokeshi Bus Stop 新幌毛志バス停 right next to the bridge on the river right. It’s not possible to take out on the river right due to a high concrete embankment/wall, so you’ll still need to take out river left and cross the bridge (300m walk). If opting to take out earlier, at the crux downstream of Ikeuri-bashi Bridge, you’ll have a 900m walk to the Nokyo-furenai-shishomae Bus Stop 農協振内支所前. Buses run northbound (upstream) three times a day in the afternoons (2pm, 4:50pm, 7:10pm from Horokeshi-bashi Bridge) and four times a day southbound (downstream) – 6:45am, 7:45am, 12:30pm, and 3:26pm from Iwachishi. Google Maps has timetabling information, here. For the brave of heart, here’s the bus company’s timetable.

By car: 

There is ample parking on the gravel river beds or gravel pull-outs on the access roads to all put-ins and take-outs. The double-track gravel road to the riverbed under Horokeshi-bashi Bridge at the take-out can be quite rough – no issue with clearance, but non-4wd vehicles may struggle. We’d recommend taking a walk down the road before driving it to make sure.

Physical maps
Official Topo Map: Furenai (振内) – map no. NK-58-8-12-4

NOTE: The official 1/25000 topo map(s) above can be purchased for 350yen from Kinokuniya bookstore next to Sapporo Station or online (in Japanese).

route safety

This section of the Saru is relatively close to civilization (or at least roads) for the entirety, so escape in an emergency is relatively straightforward. Note, however, that this section of river is relatively unconstrained by stopbanks. This means that any flood events will (and do) change the nature of the rapids from year to year. In the two years since we paddled this section of river, we have reports (from Mari and Greg) that some of the rapids have indeed changed. If in doubt, scout first – the main highway runs close to the river in places, so it’s possible to scout most of the river before paddling it.

Weather forecast weather forecast for Saru River


Onsen nearby

About 11km downstream from the take-out is the excellent Biratori Onsen Yukara びらとり温泉 ゆから (location, 500yen, 10am-9pm). The outdoor pools face onto the forest, and there’s also a private onsen available for hire (2,700yen for one hour, plus 500yen per person entry). The attached restaurant (11am-2pm, 4pm-8pm) has a great array of menu options.

Extra Resources

The Book of Leisurely Hokkaido Rivers by Ishimoto (2009), p. 74-75

Guide Options

If you’re interested in paddling this section of the Saryu with a guide, consider contacting Hokkaido Outdoor Adventures (HOA) for a bespoke tour.

Support us

Like this content? Buy the team a coffee. 50% of tips go to the Hokkaido Wilds Foundation.

Show Full Route Notes Close Route Notes

Route Trip Notes description of the route (translated)

Although this section is described by some as ‘for beginners,’ when I paddled it, the river was in a completely different state due to snow melt, and it was a very hard descent. I was particularly gutted to find a place before the Horosaru Bridge where there was a huge wave in a straight horizontal line, perhaps hidden by a low weir. After that, we descended through the high-wave rapids and managed to reach the finish line downstream of Ikeburi Bridge without incident. The road runs close to the river, so even if it’s your first time paddling the river, it’s possible to scout the river and get an idea of what the river is like beforehand.

This was supposed to be a fun, relatively easy paddle to get us warmed up for the Saru gorge section further upstream the next day. Right off the bat, however, this so-called ‘beginner-friendly’ section of the Saru was rowdy.

It all started peacefully, however, as we got ready to paddle, under dark and moody skies.

The riverside, in typical Japanese style, sign told us to keep our ears out for the warning sirens should the dam release a large amount of water in a hurry.

The crew consisted of Haidee and I (Rob), Mari and Greg, and Taku paddling solo. We were all thrilled at the condition of the river. Not too high, not too low. Just right.

We had three vehicles, so we took care of the shuttle fairly quickly. We scouted what we could from the road, and were happy we’d done so. There were a couple of rapids that we were able to run without scouting once on the river, due to their proximity to the road.

One such rapid was the one right next to the road, separated from the road by a high concrete wall. Center to start, moving to the left part way though, for a great wave train finish.

There was one rapid we spent more time scouting from the riverside. It was a relatively shallow entry, with plenty of rocks threatening to spin a canoe off course. Once in the main flow though, it was straight forward.

Another was the nasty chute downstream of Ikeuri Bridge. We spent a lot of time walking up and down the shoreline, trying to spot any canoe-breaking rocks in the final drop before the wave train. And there was also the concern about the concrete blocks on the river right – it looked as though the water was pushing mostly to that side.

In the end, we all ran it well, with no capsizes.

The remainder of the paddle was easy – just a few swifts, and some nice Autumn-esque colors on the trees.

For the final shuttle back to the put in, we channeled our inner Kayak Shuttles of Doom to get all the canoes back to the put-in in one go.

Comments | Queries | Reports

Done this route to Saru River, or other waterways nearby? Thinking of doing it? Please post any feedback, reports, or queries here. Thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

See More Like this

Hokkaido Wilds Foundation

We’ve got affiliate links on to help fund the Hokkaido Wilds foundation.

The Foundation gets a small commission on sales from affiliate links, but we only link to stuff we think is worth checking out for people keen on the outdoors in Hokkaido and Japan.

The Hokkaido Wilds Foundation is a fund where 100% of funds are donated to Hokkaido volunteer groups involved in sustainable, safe, and responsible access to the Hokkaido outdoors.

Learn more here


Filter by location

About Filters

REGION: The general mountain/geographical region the route is in.

BEST MONTH(S): Time of year a route is suited to visiting. Some pop all season, some are more limited.

DIFFICULTY: How strenuous a route is, and how technical it is. Full details here.

FREERIDE/SKITOUR: Very subjective, but is a route more-of-a-walk-than-a-ski or the other way around? Some routes are all about the screaming downhill (freeride), some are more about the hunt for a peak or nice forest (ski-tour). Some are in between. 

MAIN ASPECT: Which cardinal direction the primary consequential slope is facing, that you might encounter on the route. More details here.

ROUTE TAGS: An eclectic picking of other categories that routes might belong to.

SEARCH BY LOCATION: You can find routes near your current location – just click on the crosshairs (). You may need to give permission to to know your GPS location (don’t worry, we won’t track you). Or, type in a destination, such as Niseko or Sapporo or Asahikawa etc.

Please let us know how we can make it easier to narrow down your search. Contact Rob at with your suggestions.

Saru River (Iwachishi to Horokeshi) Difficulty Rating





Vertical Gain



Time ascending













GRADES range from A (very difficult) to D (easy). Hazards include exposure to avalanche and fall risk. More details here. Rating rubric adapted from Hokkaido Yukiyama Guidebook 北海道雪山ガイド.