Cobb Channel Diversion

As  a big fancy house comes into view on the left, the river splits around a long island.  The main flow stays to the left.   The main channel has a riffle that starts straight then bends sharply left. 

The right side channel is quiet and pretty till near the end of the island where this channel splits again, left back to the main channel or right into the Cobb Channel.  The Cobb Channel is a small ditch that leads further right for irrigation of lands along its length.  It may be passable with sufficiently high flows, but is normally blocked at various points along its way by dams and vegetation.

In 2008, Friant Water Users constructed a new diversion dam on this channel to divert more water into the Cobb channel.   The dam is just a pile of cobble stones and is easy to portage.    It is also easy to run, or rather scrape down, a shallow chute on the left.   The channel is narrow and makes a sharp bend to the left.  Beginners who don't make the turn at the bottom of the chute will crash into the berry bushes on the right bank and probably tip over.  The chanel following is fast and narrow, with several overhanging bushes that cause beginners to tip over.  Some years the bushes and berry bushes become extra hazardous.

Friant is legally obligated to deliver  some amount of flow (5 cfs maybe?) into the Cobb channel, but over the years the channels change and less water has flowed into this side channel.  To compensate, Friant had to release larger amounts of water into the river.   River runners benefitted because flows often were in the 300 to 400 cfs range instead of 100 to 200 cfs. 

The new diversion dam raises the level of the river at the side channel and forces more water into the side channel.   This allows Friant to lower flows down below 200 cfs most of the time. River runners had to paddle with these much lower flows, till higher restoration program flows started in 2009.   Confusing?