This photo needs editing.
Difficulty I(II)
Length 11 Miles
Flow Range 1400 - 20000 CFS
Flow Rate as of: 22 minutes ago 3020 [CFS] ℹ️
Reach Info Last Updated 10/10/2011 4:19 am

River Description

This lazy section of river through Sacramento runs all year round, but gets heavy use from floaters in the summer time.   The river is bordered by Sacramento County's American River Parkway which has bike paths, parking areas and access areas.   There are several different access locations along the river such as at Sunrise Ave - SACParks - Sunrise (PDF) and at  SACParks - Watt Avenue (PDF).

There are a number of sections of swiftwater and riffles, but San Juan Rapids are the notable excitement.   San Juan hole is good for playboating at many flow levels.   

Sunrise Avenue is the start for the paddling portion of Eppie's Great Race. This long standing triathalon draws nearly 1,000 paddlers every July.

Other Information Sources:  
American River Main Stem California Creekin'.
American River Parkway
Folsom Dam State Parks website  
Sacramento State Aquatics Center at Lake Natomas  on the upstream side of Nimbus Dam.
Nimbus Dam
Nimbus Fish Hatchery is located just below Nimbus dam.


Folsom South Canal: 
Water is diverted at Nimbus dam into the Folsom South Canal for municipal and industrial use south of Sacramento.   The canal has a capacity of 3,500 cfs, but this author is unable to find actual flow records as of Nov 2010.   There is a bicycle path along the canal and an organization dedicated to developing a Folsom South Canal Corridor Plan.    The canal is part of the Auburn Folsom South Project of Bureau of Reclamation.


Nimbus Whitewater:  
Michael Picker Michael Picker is offline wrote at in 2010
Remove the weir at Nimbus Dam and build a play wave near Hazel Av

Update from Nimbus Whitewater: Remove the weir at Nimbus Dam and (probably not soon) build a play wave near Hazel Avenue?

The US Bureau of Reclamation (BuRec) has been considering removing the old and costly weir that obstructs the lower American River just below the Nimbus Dam. (That’s a ways above San Juan). If BuRec removes the weir, Nimbus Whitewater has studied the potential for building a play wave at the site of the weir. The results will be convenient, but probably not spectacular, depending on the design and the varied river flows at the site.

BuRec and the California Department of Fish and Game (CDFG) have issued their draft Environmental Impact Statement and Environmental Impact Statement (DEIS/DEIR). To read or download the document, go to The selection of an alternative doesn’t authorize a play spot, but removing the weir makes a future plan possible.

You can submit written comments until November 30th, 2010 and there are two open-house sessions set for November 4th; the first from 2:00 pm to 3:30 pm and the second from 6:30 pm to 8:00 pm. Both the sessions will be at the CSUS Aquatic Center at 1901 Hazel Avenue (right next to the Nimbus Dam along Hiway 50).

For other ways to participate, see What You Can Do below.


The environmental document looks at three different alternatives:

a. Alternative 1 would remove the weir and open the river to navigation, and replace the existing fish ladder with a new “fish passageway.” NOTE: The plan doesn’t study or authorize a play wave or whitewater features in the river, but removing the weir allows discussion, engineering studies and possible construction of a play wave at the former location of the instream weir. We’ll still have to lobby the County of Sacramento to remove an ordinance that bans boating within 1,000 feet of Nimbus Dam. Alternative 1 costs an estimated $6.5 million. (CDFG is looking at some sub-alternatives related to limits on fishing to prevent spread of the New Zealand mudsnail. Clean those boats…)

b. Alternative 2 replaces the existing weir with a new and stronger structure structure just upstream. This alternative costs an estimated 12 million and is not fun.

c. The No Action Alternative (the third alternative) keeps the existing weir in place, but costs about $1 million per year (this figure comes from past comments from BuRec staff to author).

BuRec prefers Alternative 1, as does Nimbus Whitewater.


This has been a slow process, and started after the floods of 1997.

In the early years of this millennium, Nimbus Whitewater worked to have an Olympic slalom course designed and built at the Nimbus Dam as part of San Francisco’s bid for the Olympics. BuRec’s plans to remove the weir came up during those discussions. After SF dropped out, we looked at the potential for a play spot at the site of the weir, including some hydrologic studies. The studies found potential for a wave there, but didn’t include engineering. BuRec has been open to recreational opportunities if the weir has removed, but will study the play wave only after that final decision is made. The Draft EIR is an important step.

What you can do:

1. Become a member of Nimbus Whitewater an informal, unincorporated association advocating for whitewater recreation opportunities at Nimbus Dam.

2. Feel free to send your own comments on the Draft DEIR/DEIS. Email to Dave Robinson at BuREC at and to Joe Johnson of CDFG at Again, the deadline for written comments is November 30th. Look at the discussion regarding recreation in the Executive Summary (page ES-7); identification of the potential for leaving a portion of the weir in place to create a whitewater structure (page 1-11), and description of opportunity for a play wave at the site of the weir if removed (page 3-31.)

3. Attend the open house sessions on November 4th.

Nimbus Whitewater comments:

Mr. David Robinson,
US Department of the Interior
Bureau of Reclamation
Mid-Pacific Regional Office
7794 Folsom Dam Road
Folsom, CA 95630

Mr. Joe Johnson,
California Department of Fish and Game
1416 9th Street, 13th Floor
Sacramento, CA 95814

Nimbus Whitewater Comments on Nimbus Hatchery Fish Passage Project Draft Environmental Impact Statement/Environmental Impact Report

Nimbus Whitewater is an informal association of recreational advocates whose members support additional whitewater kayaking opportunities along the lower American River. In the past, we’ve discussed the potential for a whitewater play spot if the Nimbus fish weir is removed, and down river whitewater boating access for kayaks and canoes along the re-opened sections of the lower American newly accessible if the weir-obstructions are removed.

We favor Alternative 1 on account of the improved recreational access, but are currently silent on the two alternatives (1A and 1C) proposed for study and comment by the California Department of Fish and Game. We understand that the decision to select Alternative 1 does not by itself create any additional access for paddle watercraft, but is an important first step to opening this section of the river.

Michael Picker


Rapid Descriptions

Nimbus Fish Weir

Class - N/A Mile - -0.45

Boating is not allowed within 1,000 feet of Nimbus Dam by order of the county of Sacramento, possibly because of this weir.  However, there are reports that people do launch and float down from above the weir when the fish barriers are not in place.   Some people have surfed below the weir at high flows.  There may be various hazards at this weir.  

There are Studies to remove, relocate or alter this weir.

Sailor Bar Launch Ramp

Class - N/A Mile - 0
Rapid Thumbnail Missing

This is the highest legal put in for launching onto the lower American River.  It is on river right.


Class - I Mile - 0.6
Rapid Thumbnail Missing

This appears to be the start of a very long riffle or rapid.

Sunrise Avenue

Class - N/A Mile - 2.3
Rapid Thumbnail Missing

Sunrise is possibly the most used put in for floating the lower American.  There are large parking areas for river access on both sides of the river. 

San Juan Hole

Class - II Mile - 4
Rapid Thumbnail Missing

Ideal levels for the San Juan hole are between 1,400 and 3,100 cfs with 2,100 cfs primo. At 1,400 cfs it a shallow, rocky and sticky hole; at 2,100 cfs it is a gently retentive hole that is great for cartwheels and loops; at 3,100 cfs it is a very fast wave with a foam pile that still gives up spins, blunts and an end or two.


Gage Descriptions

The lower American River, below Nimbus Dam has boatable flows all year round.   Flows are highest in the spring ranging from 4,000 cfs in drier years to 10,000 cfs in average years and much higher in wet years.  Flows are lowest in the winter, but do not drop below 1000 cfs in most years.


Water from Folsom Reservoir is released from the dam through a powehouse to generate electricity.  Flows vary during the day according to power demand.  Nimbus dam forms a much smaller reservoir just big enough to reregulate or smooth out the variable flows from Folsom.    Water from Nimbus is also released through turbines to produce electricity.   A large portion of the water in Nimbus reservoir is sent out through the Folsom South Canal for municipal and industrial use in Sacramento and San Joaquin Counties.


Gauge info:
AMERICAN RIVER AT FAIR OAKS    Flow and Stage - 15 minute readings.
AMERICAN R AT HAZEL AVE BRIDGE   Temperature - 15 minute readings
AMERICAN RIVER AT H STREET BRIDGE  Stage - 15 minute readings
AMERICAN RIVER AT WILLIAM B POND PARK  Temperature - 15 minute readings
AMERICAN RIVER BELOW WATT AVE BRIDGE  Temperature - 15 minute readings
   temperature - 15 minute readings.  
USGS gauge #11446500   American River at Fair Oaks  Daily average flow and daily temperature readings.

Folsom South Canal is 26 miles long and has a capacity of 3,500 cfs.
Folsom Reservoir  Hourly Inflow, Outflow, Elevation and Storage readings.

USGS Schematic of Dams, diversions and gauges on Lower Sacramento

Directions Description

We have no additional detail on this route. Use the map below to calculate how to arrive to the main town from your zipcode.

Date Flow Result Factor  
2006-08-25 n/a Fatality One Boat Trip Read More




Paul Martzen


Matt Muir


Revision #Revision DateAuthorComment
1198556 11/03/10 Paul Martzen added info links
1200736 10/10/11 Paul Martzen added photos & minor changes
1198532 11/01/10 Paul Martzen Nimbus weir info
1194327 11/14/06 n/a n/a