Merced - 7) Snelling diversion to San Joaquin confluence


Merced, California, US

Disclaimer

7) Snelling diversion to San Joaquin confluence

Usual Difficulty I(II) (varies with level)
Length 51.66 Miles
Avg. Gradient 5 fpm
Max Gradient 11 fpm

Biggest rapid, entrance


Biggest rapid, entrance
Photo by Paul Martzen taken 11/03/07 @ 1200 cfs

Gauge Information

Name Range Difficulty Updated Level
MERCED RIVER AT CRESSY
cdec-CRS 300 - 5000 cfs I(II) 00h58m 194 cfs (rc= -0.0 )
MERCED RIVER NEAR SNELLING
cdec-MSN 250 - 4000 cfs I(II) 02h57m 319 cfs (rc= 0.3 )
Good for beginners


River Description

This is a wonderful class 1 section of river, with nice scenery, busy and frequent rapids, and frequent maneuvering in the narrow channels.   It is suitable for canoes and recreation kayaks,  but there appear to be plenty of spots for whitewater playboat action as well.    This may be one of the nicer sections of valley rivers for beginning whitewater boaters.  The ratio of rapids to flatwater is very favorable.   

This section is not suitable for unsupervised beginners, except at very low flows.    There are many rapids and sections of swiftwater.   While the rapids are not large, they can tip a novice and and sweep the unwary into trees and branches.

The Merced River below Merced Falls Dam also shows the incredible devastation from past uncontrolled dredging.  Miles and miles of tall river rock mounds were left by huge mechanical dredging barges over a century ago. A thousand years from now, after upstream dams have washed away, the river will probably erode the dredging piles back into natural riverbed. Even now though a beautiful riparian zone has developed along the tamed river, attracting wildlife, fishermen, sightseers and boaters.

Each year a small salmon run returns to the limited spawning grounds below Snelling Diversion (Crocker Huffman Dam).    Salmon and Steelhead are reared at the Merced River Hatchery  which is operated by the Dept of Fish and Game.

Put in:  There is public river access just below Snelling diversion dam.    Elevation here is about 293 feet.   There is a large turnout along Merced Falls Road and a small ramp down to the water at this spot.   It is about 2.5 miles east of Henderson Park.    Most of the land between Henderson Park and Merced Falls, appears to be private and posted No Trespassing, with the exception of a few fishing access areas.

You can also explore the next section upstream, Merced— 6) Merced Falls to Snelling Diversion Dam.  Merced Falls,  is a small dam and hydroelectric plant operated by PG&E under FERC license 2467. There is fishing access only next to the dam.    A short ways upstream along the small reservoir at the junction of Merced Falls and Hornitos Roads (where a bridge crosses the reservoir) there appears to be legal access to the reservoir. At least there were no signs prohibiting boat launching. Elevation here is about 348 feet.  One can paddle across to the south side of the dam and portage around to access the river downstream of the dam. From Merced Falls it is about 3 miles to the Snelling Diversion Dam which is another portage.   Most of the gradient seems to be lost portaging the two dams. 

Access points: 
Henderson Park is about 2.5 miles below Snelling diversion and provides public access to the river as well as picnic areas.    

In the town of Snelling there is access to the river from 4th street.

The Snelling Road bridge has access on the north side of the bridge (river right).   There is plenty of parking space on the shoulder of the road.   Elevation here is about 234 feet.

Highway 59 now has shoulders for parking on the northwest side of the Merced River bridge.    A large area along the river banks have been landscaped just upstream of this bridge.

The Oakdale Road bridge has a public lot on the northwest side so people can walk across the historic Schaffer Bridge.   However, the river access is completely fenced off, with prominent No Trespassing signs.   (penal code 602)   There is of course a nice big hole in the fence where the public has been accessing this public river, via what is probably public land. 

Highway 37 / Santa Fe Ave Bridge appears to have de facto access.

McConnell State Recreation Area is on the Merced River just east of Highway 99.  The river is scenic flatwater in this area.

Hagaman County Park.  The valley Oaks from here to Hatfield are reported to be especially remarkable.

George J. Hatfield State Recreation Area   is on the river near its junction with the San Joaquin River.


Overview: 
The small opening at the put-in below Snelling diversion, opens onto a large slow water pool that is nice for warming up and paddling upstream.   Once boaters turn downstream, they immediately encounter the first of many significant small rapids.     The river alternates between wide sections of slow water and narrow sections of swiftwater and/or rapids.   Rapids are often on curves or S turns.    Maneuvering is critical to stay out of trees and frequent overhanging branches.     The section down to Henderson Park seemed to have the bigger rapids, but perhaps more flatwater as well.  The section from Henderson to the take out bridge has more narrow sections and more fast current, but more tree hazards as well.   At least in the Fall of 2007.

The difficulty of this section seems to be similar to or slightly easier than the Kings River from Pine Flat Dam to Centerville (Route 180)  in the Piedra area, though with higher danger from strainer trees.   Flow at 3200 cfs on the Merced felt similar to 7,000 or more on the Kings River. 

Other Information Sources:   
Merced River Hatchery    is open to the public, weekdays from 8 AM to 5 PM.    They raise salmon and steelhead.   However, the drive in is a couple miles of rough gravel road without direction signs.  The fish pens are locked up and there may not be anyone there unless you call ahead.   It might quicker and easier to paddle the short distance upstream from the put-in, especially during periods of low flow.
Merced Irrigation District

Merced Irrigation District Parks Department
9090 Lake McClure Road
Snelling, CA 95369
209-378-2521
San Joaquin River Group Authority  
Merced River Watershed Library  
Lower Merced River and Mustang Creek Watersheds Study

FERC Information:
Merced Falls Project: FERC # P-2467, license expires in 2014, so PG&E is probably starting or getting ready to start their relicensing process. It is a small run of the river project, but in water year 2005-2006, this project generated 13,806,300 KWH of electricity.

To search for documents related to this project go to the FERC elibrary. Enter P-2467 into the Docket number box.

Merced River Hydroelectric Project, Federal Energy Regulatory Commission (FERC) Project No. 2179, also has effects on this reach.    " The Project is located on Merced River in Mariposa County, California, and consists of 2 reservoirs (Lake McClure and McSwain Reservoir), 2 powerhouses (New Exchequer and McSwain powerhouses) and various recreation facilities on Lake McClure and McSwain Reservoir.  The Project does not include any transmission lines, canals or open conduits.  The installed capacity of the Project is 103.5 megawatts. "


StreamTeam Status: Not Verified
Last Updated: 2011-02-15 19:50:43

Shaffer Bridge signs

Detail Trip Report  Shaffer Bridge signs  @Merced 7) Snelling diversion to San Joaquin confluence, CA(836.67KB .jpeg)

Oakdale Bridge and Shaffer Bridge

Detail Trip Report  Oakdale Bridge and Shaffer Bridge  @Merced 7) Snelling diversion to San Joaquin confluence, CA(716.43KB .jpeg)

Surf Wave

Detail Trip Report  Surf Wave  @Merced 7) Snelling diversion to San Joaquin confluence, CA(804.14KB .jpeg)

Typical trees in the river

Detail Trip Report  Typical trees in the river  @Merced 7) Snelling diversion to San Joaquin confluence, CA(1.22MB .jpeg)

Abandon Ship!

Detail Trip Report  Abandon Ship!  @Merced 7) Snelling diversion to San Joaquin confluence, CA(745.48KB .jpeg)

J59 road bridge

Detail Trip Report  J59 road bridge  @Merced 7) Snelling diversion to San Joaquin confluence, CA(695.59KB .jpeg)

Flood plain

Detail Trip Report  Flood plain  @Merced 7) Snelling diversion to San Joaquin confluence, CA(571.63KB .jpeg)

Hills above flood zone

Detail Trip Report  Hills above flood zone  @Merced 7) Snelling diversion to San Joaquin confluence, CA(2.79MB .jpeg)

Low water play spot?

Detail Trip Report  Low water play spot?  @Merced 7) Snelling Diversion: down, (1.04MB .jpeg)

Riffle with snag

Detail Trip Report  Riffle with snag  @Merced 7) Snelling Diversion: down, (1.01MB .jpeg)

Biggest rapid, entrance

Detail Trip Report  Biggest rapid, entrance  Merced, CA(340.11KB .jpeg)

Stan leads the way

Detail Trip Report  Stan leads the way  Merced, CA(315.95KB .jpeg)

skipping rocks at Henderson Park

Detail Trip Report  skipping rocks at Henderson Park  Merced, CA(409.82KB .jpeg)

Approaching Henderson Park

Detail Trip Report  Approaching Henderson Park  Merced, CA(324.28KB .jpeg)

First rapid, Merced near Snelling

Detail Trip Report  First rapid, Merced near Snelling  Merced, CA(299.85KB .jpeg)

Dredge Piles

Detail Trip Report  Dredge Piles  Merced, CA(256.26KB .jpeg)


Gauge Information

Gauge Description:

Flows in this reach are most often in the 150 to 300 cfs range, which is quite low, but very safe for inexperienced boaters.  At 150 cfs, boats are probable scraping bottom in many of the riffles.   At 300 cfs most riffles should be clean but still pretty gentle.    

During October and May extra water is released down the river in accordance with agreements of the San Joaquin River Group Authority.   The historical record shows that these releases happen in most years but not in all years.   During these releases, flows jump up into the 1,000 cfs range.   It appears that the May releases tend to be higher and longer than the October releases.    A Fresno club trip in November of 2007 found that 1200 cfs was an excellent, fun and exciting flow for this reach, at least for experienced boaters.   Beginners should stick with lower flows unless guided by experienced boaters.   A flow of 250 cfs is surprisingly fun and reasonably clean.  300 to 350 would be a bit cleaner and probably just as easy and safe. 

In wet years, spring releases can rise to several thousand cfs.   Only experienced boaters such as whitewater boaters should be on the water when flows are that high.   At 3200 cfs  (Feb 8, 2011) the river is very fast and very fun for those with sufficient experience to have strong skills and boat control.   There are many strainers throughout the run which must be avoided.  Drifting into trees at high flows would be disastrous and could easily be fatal.   The flow is about 5 miles an hour as it took us 2 hours to go from Snelling diversion to J59, then just a bit more than 2 hours to go from J59 to Oakdale road.

To study daily average flows for the last few years look at MeanFLOW and change the number of days displayed to several years worth, such as 1600 days.     

Merced at Snelling: CDEC  reports 15 minute flows, in this reach below Crocker Huffman diversion dam. 
Merced below Merced Falls: USGS reports hourly flows in the non diverted reach above Crocker Huffman 
Merced near Cressey, Hourly flow table
USGS: Merced near Cressey, Historical data 
Water Temperature below New Exchequer Dam  
Water Temperature below McSwain Dam   
Water Temperature at Merced Fish Hatchery  
Water Temperature near Cressey

 

Gauge Information

Name Range Difficulty Updated Level
MERCED RIVER AT CRESSY
cdec-CRS 300 - 5000 cfs I(II) 00h58m 194 cfs (rc= -0.0 )

RangeWater LevelDifficultyComment
300 -5000 cfs barely runnable-high runnable I(II)
MERCED RIVER NEAR SNELLING
cdec-MSN 250 - 4000 cfs I(II) 02h57m 319 cfs (rc= 0.3 )
Good for beginners

RangeWater LevelDifficultyComment
250 - 400 cfs barely runnable-perfect runnable I(II) Good for beginners
400 -1200 cfs med runnable-a bit pushy runnable I-II A more fun range for experienced boaters
1200 -4000 cfs a bit pushy runnable-high runnable II Fast, nice waves, but increased danger from trees.

Report - Reports of Merced 7) Snelling diversion to San Joaquin confluence and related gauges

Reports give the public a chance to report on river conditions throughout the country as well as log the history of a river.

Reports

When River/Gauge Subject Level Reporter
1y87h13m @Merced 7) Snelling diversion to San Joaquin confluence [CA] Fast Ride! 3200 cfs Paul Martzen
1y23d13h06m @Merced 7) Snelling Diversion: down Low water play spot? 245 cfs Paul Martzen
1y27d13h12m @Merced 7) Snelling Diversion: down Riffle with snag 245 cfs Paul Martzen
4y102d08h12m Merced [CA] Biggest rapid, entrance 1200 cfs Paul Martzen

WXPort

News





No Comments

Users can submit comments.

Rapid Summary

Mile Rapid Name Class Features (Legend)
0.0Put in and largest rapidN/A
2.8Henderson ParkN/AAccess Photo
3.9Snelling accessN/AAccess
5.3Snelling Road bridgeN/AAccess
7.7Start of Restoration AreaN/APhoto
9.7J59 BridgeN/AAccess Photo
12.3Bridge (private)N/A
13.1Big Island splitN/A
13.5WeirN/A
14.6Bridge, then weirN/APlayspot Photo
18.5Oakdale Road BridgeN/AAccess Photo
23.8Road 37 / Railroad trestleN/AAccess
27.6McConnell ParkN/AAccess
30.5Highway 99 bridgeN/A
39.2Hagaman ParkN/AAccess
49.5George Hatfield State Rec AreaN/AAccess
51.7San Joaquin River ConfluenceN/ATakeout

Rapid Descriptions

Put in and largest rapid (Class N/A)

The biggest rapid is immediately below the put in pool.   At low flows (250 cfs) try to find a route to scrape down through the rocks.   At 1200 cfs there are nice waves and a horizon line about 2/3's of the way through.    At 3200 cfs, there were some fun big rolling waves.    You can walk over to the river to scout parts of this rapid from several turnouts along the road. 



Henderson Park (Class N/A, Mile 2.8)

Approaching Henderson Park

Approaching Henderson Park
Photo by Paul Martzen taken 11/03/07 @ 1200 cfs

This county park provides a convenient access point and picnic area.  There is plenty of parking, toilets, and picnic tables.   The majority of riffles are upstream of this park, so this makes a good take out for those who have only a short time and want to practice whitewater skills. 



Snelling access (Class N/A, Mile 3.9)

Take 4th street, south to its end and walk down to the river.   There is a pretty long riffle here as well as a channel split.  The main channel goes to the right. 



Snelling Road bridge (Class N/A, Mile 5.3)

There is a large enough shoulder on the northwest side of the bridge for a few cars to park.  A trail leads down next to the bridge.



Start of Restoration Area (Class N/A, Mile 7.7)

Flood plain

Flood plain
Photo by Paul Martzen taken 02/08/11 @ 3200 cfs

Looking upstream from the J59 bridge and at aerial photos, I wondered why anybody would bulldoze so much of the land along the river.   When I paddled this section at 3200 cfs, it became clear.  At high flows this area becomes a vast and beautiful flood plain.   We were paddling on a huge lake, yet with a ribbon of fast current. 



J59 Bridge (Class N/A, Mile 9.7)

J59 road bridge

J59 road bridge
Photo by Paul Martzen taken 02/08/11 @ 3200 cfs

With the construction of a new bridge over the river, there is now designated river access with plenty of parking on the northwest side of the bridge.   A trail leads down to the river and a sign states fishing regulations.

Downstream of J59, brush hazards are a bigger problem, along with deciding which channels to take.   In a few places, the channel will split, then resplit, then filter through brush.  There is generally a clear channel someplace, but it is easy to take channels that are not so clear. 

 



Bridge (private) (Class N/A, Mile 12.3)

This bridge makes a good landmark for judging time and distance.    Below this bridge, the river splits around an island, then passes through a gravel pit lake.. 



Big Island split (Class N/A, Mile 13.1)

The river forks around a very large island.   The left fork loops to the south and back in 1 mile.  The right fork cuts directly across in 1/3 mile, but at the end has nasty tree and brush hazards.  We got through (feb 8, 2011, 3200 cfs), but wasted time trying to find a route, scared ourselves even on the route we did find and fought with berry bushes.    Take the left route.

Mileages from this point downstream are based on taking the right fork but will be adjusted soon.



Weir (Class N/A, Mile 13.5)

Some sort of weir backs the river up to divert water into a ditch on the left.  The weir is not visible at high flows, so it is probably just a low gravel weir.  



Bridge, then weir (Class N/A, Mile 14.6)

Surf Wave

Surf Wave
Photo by Paul Martzen taken 02/08/11 @ 3200 cfs

A private bridge at mile 14.57 indicates that there is a weir in the river, immediately downstream.   At 3200, the weir made an excellent looking play spot with a wide wave.    Part of the wave was breaking.    There was plenty of room on either side to paddle around the wave.



Oakdale Road Bridge (Class N/A, Mile 18.5)

Oakdale Bridge and Shaffer Bridge

Oakdale Bridge and Shaffer Bridge
Photo by Paul Martzen taken 02/08/11 @ 3200 cfs

There is public parking on the northwest side of the Oakdale road bridge.  From the parking area you can walk out onto the historic Shaffer Bridge.  It is a nice stroll and gives a good view of the river downstream.  The up river view is blocked by the newer bridge.   Public access to the river is prohibited by penal code 602.  Chain link fences completely block access, except where there is a big hole in the fence with a trail leading down to the river.   We were not hassled when we left a car here in February and used this area as a take out.  Might be very different in the summer.

Some water agreements require the Merced Irrigation District to provide certain minimum flows to this point in the river depending on the time of year.   A gauging station is mounted on the downstream side of the Shaffer bridge towards the middle.

There probably are not any or many riffles below this point.



Road 37 / Railroad trestle (Class N/A, Mile 23.8)

There appears to be a wide shoulder on the north side of the bridge where cars can park.  Trails lead to the river. 



McConnell Park (Class N/A, Mile 27.6)

There is public river access at this state recreation area.



Highway 99 bridge (Class N/A, Mile 30.5)

There does not appear to be any public access to the river in this area. 



Hagaman Park (Class N/A, Mile 39.2)

Public park on the river provides access.  From here down to Hattfield,  the river is notable for one of the most impressive stands of huge Valley Oak trees in the region. 



George Hatfield State Rec Area (Class N/A, Mile 49.5)

This state recreation area straddles the river.   Parking and access is on the north west side, from Kelley Road. 



San Joaquin River Confluence (Class N/A, Mile 51.7)

Hills Ferry Road crosses the San Joaquin at the Merced confluence.   There is a wide shoulder and trails to the river on the south west side of the bridge.   Elevation is about 57 feet above sea level. 




Do more than just check gauges; join over 5,000 AW members today.

Join_or_Renew_Logo-200px

Join or Renew


Or, consider donating

Donate_Logo-200px

Donate


General Nonmember Message


 reach  
 state  
 reachlink  
 7) Snelling diversion to San Joaquin confluence, Merced California, US (mobile)