Boise & Garden City

Rocky Barker: Floating into the future on the Boise River

It’s a sure bet that with the high temperatures we’ve seen this week, the Boise River will be filled Friday with rafts, inner tubes and other craft.

The floating season is open, and Boise residents and visitors will flock to this scenic and recreational artery through our city. ( Follow this link for details and advice on river rentals starting Friday.)

It’s not as if most of us don’t see the river daily. But something about leisurely floating at the river’s own pace gives you time to think about the big picture. Drifting past Boise’s parks, through several of her neighborhoods, under her bridges, around her islands, over her diversions, past Downtown and finally to the Ann Morrison takeout shows how connected we all are to the river that runs through our lives.

A third of all Idahoans live in the Boise River watershed, which we share with 150 species of birds and dozens of mammals, from mice to moose to mink. This is not the remote Middle Fork of the Salmon River.

Dams hold back Boise River flows that would reach about 14,000 cubic feet annually if the dams weren’t there, and which now peak at an average of 4,500 cfs. Sprawling irrigation canal systems carry most of those flows to the farms and fields of the Treasure Valley, allowing farmers to grow hundreds of millions of dollars of crops.

Our forebears wrestled the river into its current long, straight channel. That makes floating easy and reduces the snags, side channels and meanders of a healthy natural river. But we’ve lost some of its natural ability to absorb flood flows and preserve its hydraulic complexity. That means we have to work to keep our stately, shady cottonwoods growing on its banks, since they are naturally seeded and fed sediment from floods.

Even with the dams in place, the U.S. Army Corps of Engineers and the Bureau of Reclamation say a year will come when the dams’ federal managers can’t hold back all the water that will be in the Boise River system. The worst we’ve had since the dams were built was about 8,300 cfs in 1983, but it’s just a matter of time when a big water year will overwhelm the skill and planning of the dam managers.

That’s why the Corps is in the early stages of studying alternatives for making us better able to handle that future flood. Throughout the country, the agency has developed options to reduce the flood threats, such as encouraging wetlands and using flushing flows in the spring to increase channel capacity.

But right now, the Corps is following the lead of the Idaho Water Resources Board, which wants more storage capacity. The Corps has determined the most cost-efficient option is raising Arrowrock Dam. Critics say that this won’t be cheap and that the continuing conversion of farmland to residential development has reduced the need for more water.

This will be a continuing debate in the Valley. Meanwhile, people on both sides of that debate are working together to develop plans and strategies to improve the ecological health of the river. The Boise River Enhancement Network represents a wide coalition of sportsmen, canal companies, environmental groups and local, state and federal agencies.

BREN, as it calls itself, has developed a draft plan that lays out a vision for making the Boise River more resilient. It has an open house at the offices of Idaho Rivers United, 3380 Americana Terrace, on June 17 from 5:30 to 7 p.m. if you want to learn more.

Anglers know that the Boise River through town has become one of the state’s fine fisheries for rainbow and brown trout. But I didn’t know just how fine until I talked to Idaho Department of Fish and Game fisheries biologist Joe Kozskay.

I had planned to rant about the agency’s proposal to eliminate the trophy fish regulations in place for two miles of the river near my house in Southeast Boise. Those regulations require anglers to release all but two trout that are larger than 14 inches. Kozskay says the regulations are unnecessary since anglers keep only about 5 percent of the trout they catch all along the city’s entire stretch of the river, even where there are no special regulations.

The numbers of wild trout have exploded since dam managers began providing stable winter flows in the river more than 16 years ago. Wild trout populations have increased 17-fold since 1994, putting the city section of the Boise River in the top 20 percent of wild trout river stretches in the state.

Instead of just removing the trophy regulations in Southeast Boise, perhaps Fish and Game should consider managing the entire city stretch for the sustainable wild trout fishery it has become. That would mean a halt to releasing extra hatchery rainbow in the river and instead using them to stock ponds and other river stretches that can’t sustain a fishery naturally.

Dams, irrigation, floods, healthy riverbanks and cottonwoods, and big trout. Those are the things I think about when I’m floating the river or casting in the evening when the caddis hatch comes off. Welcome summer yourself with an afternoon or evening on the Boise River and see what this uniquely Boise experience does for your imagination.