Flows from Lucky Peak Dam increased again on Friday because more precipitation is in the forecast for the Boise River drainage.
Flows through the Boise will increase 250 cubic feet per second from the current flow of 8,550 cfs to approximately 8,800 cfs on Friday. Water levels are getting close to what's considered "moderate" flooding; a flow rate of 7,000 cfs is considered flood-stage level at the Glenwood Bridge gauge on the Boise River.
Water managers say releases from the reservoir system are necessary to reduce the risk of more severe flooding later in the spring, which could occur with rapidly melting snow and precipitation. An extremely large mountain snowpack and above-normal precipitation means less flood control space in the Boise River reservoirs (Anderson Ranch, Arrowrock, Lucky Peak). There also hasn't been a demand for irrigation water in the Treasure Valley because it has stayed so wet and cool.
The Bureau of Reclamation says additional sections of the Boise Greenbelt adjacent to the river will be submerged, and erosion of river banks will continue to be a problem. Emergency management officials are urging you to heed warnings and stay off the closed and dangerous sections of the Greenbelt. The pathway is still shut down in Eagle and most of Garden City and Boise. All but about 11 miles of through Ada County are closed until the dangerous river conditions let up, which will likely be the end of June.
Boise River reservoirs are at approximately 68 percent of capacity. More flow increases are possible in the coming weeks, depending on weather conditions.
As flows remain swift and high, you can see a spectacle many have been anxiously awaiting all season: the "rooster tail" at Lucky Peak! You can view the classic water display Saturday and Sunday from noon to 6 p.m., but officials are strongly urging you to be safe out there.
Visitors on Saturday reported heavy traffic and scarce parking.
"It takes every bit of the 2 1/2 hours to go through the driving tour," Alicia Phelps posted on the KTVB Facebook page. "I would recommend people either take the greenbelt down or pay to park."
This is one of our areas most popular attractions and we haven't seen it since 2012. The rooster tail discharge comes through the dam's outlet slide gates, which dissipate the water's energy by shooting it hundreds of feet through the air and creating an arch of spray into the Boise River.
But don't take our word for it - check it out for yourself this weekend!
"It's a huge spray of water and people love to come out and take a look at it," Army Corps of Engineers Park Ranger, Carolyn Smith, told KTVB. "We used to actually previously discharge water from that tunnel on a daily basis and they discontinued that several years ago when the powerhouse was put in."
Water managers say they're basically turning one faucet off -- these auxiliary tunnels -- and turning another faucet on.
"We're not increasing flows into the Boise River in order to do this," Smith said.
The water used to create this display comes from the required rates they're already releasing from the reservoir.
"The powerhouse is currently using some of that water. whatever is in excess to that, then we'll discharge it through the rooster tail. Weather conditions need to be right, staffing conditions," Smith said.
The U.S. Army Corps of Engineers expects thousands of people will come witness the rooster tail this weekend.
"Be prepared for a lot of crowds," Smith said.
The only continuous, extended stretch of Greenbelt that's open is the route from the Warm Springs Golf Course up to Lucky Peak Dam.
It can be dangerous in certain sections. Right next to the path, there's a steep hill dropping into the river as you approach Lucky Peak. And in one long section, there's no line dividing the path.
"It can be rocky in places, there might be potholes, some of it is dirt," Smith said.
A lot of people -- bikers and pedestrians -- will be using it to get to the show.
"We're gonna have a lot of traffic on the Greenbelt as well, so people with bikes, kids, dogs, things like that just trying to be respectful for each other's space and opportunity to see the rooster tail," Smith said.
With that many people...
"Safety is our biggest concern," she said.
The Army Corps of Engineers is concerned about people parking in places that are going to cause traffic hazards.
"It's gonna be very congested," Smith said.
To reduce congestion and delays, Lucky Peak Dam and lake staff created a driving tour for people to see the water works from their car.
You'll head up Highway 21 to the top of the dam, turn right to cross the dam, and then follow that down to the service road.
"We'll have people positioned there telling people where to go, giving them information," Smith said.
You can park at Discovery State Park and Sandy Point State Park. There is a $5 entrance fee. However, free parking is extremely limited and you won't be able to park along Highway 21, the access road leading down to Sandy Point, or the road across from the dam.