Tailwaters are rivers below dams that release water from the bottom of the reservoir. Releasing water from the bottom vs the top helps keep the outflows cooler in the summer and warmer in the winter—this is called the Tailwater Effect. But not all Tailwater Dams are built and managed the same which can impact the Tailwater Effect and influence outflow water temperatures. Lucky Peak Dam, which feeds the Lower Boise River is built and managed differently than the Anderson Ranch Dam, which feeds the S.F. of the Boise River. Understanding how tailwater-dams impact water temperature will help you find more productive water and improve your fishing throughout the year

FUN FACT

Do you know why ice floats, or why ice forms on the top of a lake, and not on the bottom? It is because water has a unique property that makes the solid form less dense than the liquid. This is important to fisherman because 39 degree (F) water is the most dense, which means it sinks to the bottom of the reservoir where water is released.

WINTER

Anderson Ranch Dam

On the S.F. of the Boise the Tailwater Effect is your friend in late fall and early winter because that large blanket of water results in water temps staying 40 – 50 degrees in November and December compared to the freestone section above dropping down into the 30’s. The warmer water coming out of Anderson Ranch dam results in longer hatches, active fish, and awesome fishing! Figure-1 shows how water temperatures coming out of the dam stay elevated into December while water temperatures drop into the 30’s on the freestone section of river above the dam at Featherville. But the warming from the Tailwater Effect is limited to the first 5-10 miles of the river, after that the influence of cold days, freezing nights and side streams drop water temperatures, as shown by the temperature at Neal Bridge 26 miles below the dam.

Lucky Peak Dam

The Lower Boise River doesn’t experience the same winter Tailwater Effect as the South Fork because Lucky Peak is drawn down for irrigation each year and the outflows from Lucky Peak come from a higher elevation in the reservoir. This draw-down and outflow location means the water released is influenced by the surface water temperature which causes water temperatures to drop quicker and get colder on the Lower Boise River in the winter than the S.F. of the Boise. Figure 2 shows water temperatures released from Lucky Peak Dam from fall through winter and Figure-3 shows Lucky Peak winter water elevation and where outflows originate. You can see that the reservoir level drops into the outflow-zone starting in October and stays there through February, driving outflow water temperatures down into the mid 30’s all winter. Winter water temperatures on the Lower Boise River will warm a bit on sunny days as you go downstream which can make fishing better in the afternoon between Glenwood and Star.

SPRING

As winter turns into spring and the sun gets higher in the sky, water starts warming. The greater the sun exposure and the more solar cycles, the more it warms which results in water getting warmer the further downstream you go. This pre-runoff time can be some of the best fishing of the year as the warmer water gets the hatches going and makes the fish HUNGRY! However, while water is warming downstream the water temperature being released from Anderson Ranch and Lucky Peak dams gets stuck in the upper 30’s, which makes it advantageous in the spring to fish further downstream where water has time to warm up. Figure 4 shows how the water temperature increases as you go downstream on the Lower Boise River. While water temperatures at Lucky Peak stay cold all day the river below warms up enough to see some hatches and more active trout.

SUMMER

In the heat of summer, freestone rivers can get too warm for good trout fishing, but the temperature of water below a tailwater dam is usually cooler because of the deep blanket of water insulating outflows from the summer heat. On a tailwater river you can often escape higher water temperatures by fishing closer to the dam that is releasing cooler waters. On a freestone river one way to combat the heat of summer is to fish further upstream where the river has seen fewer “solar cycles” of warming.

Anderson Ranch Dam outflows into the S.F. of the Boise remain cool all summer long running around 55 degrees. However, water temperatures on the Main Boise River are again impacted by the irrigation draw-down of Lucky Peak, causing outflow temperatures to rise into the mid 60’s by the end of August, and even higher in low-water years. Trout have a range of preferred water temperatures and stop biting when the temperatures get into the upper 60s, so it is best to seek out cooler waters when these conditions exist. Fishing in overly warm water also increases the mortality rate of trout caught and released.

A recent Idaho Fish and Game study on water temperatures found that:

The study found that mortality was 69% higher for trout landed at 73°F water temperatures than for those landed when waters were less than 66°F. These results suggest that higher water temperatures were indeed decreasing the survival of caught-and-released trout. However, catch rates were much lower (77% lower!) at the higher water temperatures above 73°F, and much better when temperatures were below 66°F. So while mortality was higher at the hottest temperatures, the number of trout caught was much lower because it was much harder to catch fish at those warmer temperatures. This phenomenon is well known to trout anglers, who often stop fishing in the heat of the day because catch rates are poor compared to cooler times of the day.

THE THEMOMETER IS YOUR FRIEND

Checking water temperatures can help you find the most productive water and anticipate what bugs will hatch. Checking water temperatures online using BVFF’s Local Waters web page can help you plan your trip and carrying a quality stream thermometer (FishPond and Orvis have good ones) can help you adjust your fishing plans on the river. For more information on how to use a thermometer to improve your fishing, see my article Using A Thermometer To Improve Your Fishing.

REFERENCES

• BVFF’s Local Waters web page. 

• Water flow and temperature information can be found on USGS and BofR Hydromet websites .

• Water temperatures on the Main Boise River were obtained from the City of Boise through a public records request of water quality data.

• BVFF Conservation Blog

• Using A Thermometer To Improve Your Fishing

• Idaho Fish and Game Water Temperature Study

It's February, and time to chase some mountain whitefish!  Mountain Whitefish are native to our local rivers and an indicator of water quality. The Boise River in town has a healthy population of Whitefish and the S. F. of the Boise has some of the biggest whitefish in the area.

Whitefish are more tolerant of the cold winter water and are more eager to take a fly than their trout cousins.  One key to catching whitefish and trout in the winter is to get the fly down to the bottom where fish are holding.  A drop-shot rig is a great way to do this and can be fished with or without an indicator.  Here is how to build a drop-shot leader.  Additional information on Euro-Nymphing rods and techniques can be found on the BVFF Euro-Nymphing page.

Whitefish have small mouths so it helps to use smaller nymphs. Some good patterns to try are:

1. #16 Black or Red Zebra Midge
2. #16 Olive Thread Frenchie
3. #18 Rainbow Warrior
4. #16 Frenchie
5. #18 Red Brassie
6. #14 Blowtorch
7. #12 Prince Nymph

Additional Information.

BVFF Whitefish Derby (VIRTUAL) and (IN-PERSON)

1. Whitefish Ed
2. Idaho Fish and Game Whitefish Information
3. The Mighty Whitey
4. Chasing Mr Whitey
5. A Native Friend

Boise has seen a few warmer days with nights above freezing, which is a pattern that can help warm rivers and improve fishing. In late Fall and early winter you can find warmer water by fishing up close to a tailwater dam, but this time of year when you have a string of warmer days and nights the opposite can be true.

Winter outflows from the dam are locked into a constant temperature coming out of the bottom, which is usually around 39 degrees below Anderson Dam and 36-37 degrees below Lucky Peak Dam. Warmer days and nights will allow that water to warm up as you go downstream.

Here is a look at water temps on the Lower Boise River at Glenwood bridge and at Caldwell so far this month. You can see the Boise River at Glenwood is warming a couple of degrees and getting into the upper 30s while the river down at Caldwell is up into the lower 40s.

Just a degree or two of warming during the day can make a big difference. Fishing downstream sections closer to Star can pay off this time of year and focusing on the last few hours of the day can be productive as water temps are at their maximum. This trout was caught on January 2nd between Eagle and Star, the last hour of the day.

Paying attention to water temperature can really improve your fishing. Checking BVFF's Local Waters page for water temperatures on local rivers is a good way to plan your winter fishing.  For more information on how water temperature impacts fishing, see our article Using A Thermometer To Improve Your Fishing.

BVFF members Al & Gretchen Beatty were recently awarded the Federation of Fly Fishers (FFI) Award of Distinction for their years of service and contributions to FFI and promotion of fly fishing.

Al and Gretchen and their achievements are highlighted in the recent FFI magazine publication FlyFisher (Winter 2022).

The criteria for the FFI award is described by FFI as follows:

FFI Award of Distinction (formerly Lapis Lazuli Award)

The ultimate award of Fly Fishers International. Thus, the consideration for individual achievement is extremely strict. Services and contribution to FFI must be prominent and extraordinary, and above all, they must be long term (at least 8 years). They must be significantly above the criteria that would merit consideration for any other award.highest level of recognition bestowed on an individual who has demonstrated.

The criteria are as follows:

Eight years of service to FFI is required.

Service should be voluntary. Time as a paid employee of the Federation, although not totally discounted, would merit minor consideration.

Individual should not have previously won the award.

To preserve the integrity of this award, it is recommended that it be awarded judiciously and infrequently, but it is not intended that the frequency stipulation deprive a truly deserving individual.

This award is the ultimate award of the Federation. Thus, the consideration for individual achievement must be extremely strict. Services and contributions to the Federation must be prominent and extraordinary, and, above all, they must be long term. They must be significantly above the criteria that would merit consideration for any other award.

Election shall be by the Executive Committee. The vote shall require a 2/3 majority. The Chair of the Awards Committee shall be notified prior to the meeting of the Committee to avoid conflict or duplication. Nominations for this award should be made directly to any member of the executive Board.

Tom Old and George Butts presented DIY Alaska at the November general membership meeting.  Tom and George described the planning and true costs of organizing a Do-It-Yourself trip to Alaska and comparison with a trip with a lodge / outfitter.  Tom and trip members spent a year planning and organizing their recent fall trip.

A reference sheet has been posted with information, references, and knowledge learned in their planning and experience with this trip.  You can find the document HERE.

Did you know that your Gore Tex waders will perform better and last longer if you wash them? The same goes for your Gore Tex (and other waterproof fabric) rain jackets. In fact, hanging your Gore Tex raincoat up while it is dirty is a recipe for disaster as the accumulated body oils will break down the Gore Tex membrane and cause it to fail.

Fall is a good time to wash off the summer load of sweat, sunscreen, bug spray and gink. It's easy--here is how I do it. I've listed links below to specific wader manufacturer recommendations. Note that Simms cautions about using old agitator-style washers. As an alternative you can hand wash your waders with a little rub-a-dub-dub in the bath tub.

WASHER INSTRUCTIONS

Step 1: Examine your waders for damage, like seam-seal tape that is coming off. If you find that, then you should repair it with some Aquaseal first before washing them.

Step 2: Look at your waders to see if they have a tag with washing instructions and follow the recommendations.

Step 3: Empty all the pockets! If you have a zipper, then zip it up! If you can, take off the suspenders.

Step 4: Use a small amount of a mild detergent without any bleach or fabric softener. Even better, use some Nikwax Tech Wash which is designed for breathable materials and will help revive the DWR.

Step 5: Set the washer to a hand-wash or delicate setting, and turn OFF the spin cycle. It helps to set the washer to a "full load" to make sure you get the waders fully immersed and I like to put a cotton towel on top of the load, to help keep the waders submerged.

Step 6: When you go to pull the waders out, be prepared for them to have some water trapped in the booties. Turn them inside-out to flush out excess water and hang them upside-down outside to dry (avoid using the dryer as the heat can do damage). After a few hours turn them right-side out to finish drying.

Oh, and it's a good idea to check inside your washer for any tidbits left over. Even though I carefully check my pockets there is usually a piece of monofilament or a split shot that I missed.

SIMMS Wader Care: 

PATAGONIA Wader Care:

By Dave Shuldes

As I write this I have just put the finishing touches on flies for my annual trip above 8,000 feet in Central Idaho. I love the staging of gear nearly as much as the trip itself. There’s only one shot at getting the kit right for a week in the wilderness, so every detail is double-checked. My fishing won’t be measured by numbers. A few photos of some exceptional fish along with the adventure and the camaraderie of a safe backpacking trip with friends will be all I need.

In addition to taking care of my gear and my friends, one of my goals will be to appreciate and take care of the fish found in these alpine lakes. Just like my camping list, this involves details. When a beautiful alpine lakes’ brookie, cutthroat, golden, grayling or rainbow comes to hand, I’ll show my appreciation for the fish by using these guidelines:

• I’ll use barbless hooks.
• I’ll keep my hands wet while handling the fish and will cradle it rather than squeezing it.
• I won’t touch the fish and will keep it from touching dry surfaces like rocks and grass.
• I’ll keep the fish in the water as long as possible, minimizing air exposure and handling time.

“Take only photos, leave only footprints” as backpackers say. Photos are a key part of my passion for fly fishing and the wilderness. But I won’t appear in any of those fish pictures… I’ll save that for a group shot at the camp. The fish itself is the main event. I don’t stress every fish with the photo process - I will limit that to the memorable ones. Some fish are extraordinary, not only by size but also by vibrancy and markings. I’m looking for colors, spots and details to appear in the frame. Flared fins and a submerged head are a bonus. Ideally the fish will be swimming in the water on the end of the line (to me it’s worth the risk of losing the fish before the photo is taken). I’ll have everything set up on my camera long before the fish is hooked. Holding the fish by the line with the hook still in its mouth in shallow water, I’ll shoot a rapid succession of random shots. I can crop, discard and edit later on. I’ll minimize the photo session time with any one fish and release it quickly after one series of shots.

For river fishing, I’ll add use of a net to my fish handling and take special care to release quickly when water temps are warm. Using the net as a “live well” to hold the fish while it’s reviving is a great opportunity to frame a vibrant swimming photo.

A fish mortality study by R.A. Ferguson and B.L. Tufts considered time a trout was held out of the water. Their findings showed that fish released and kept in the water had a mortality rate of 12%. Fish lifted from the water for 30 seconds had a 38% mortality rate. 72% of the fish held out of water for a full minute died. All research has its flaws, but holding fish out of the water can be harmful if not lethal. I would like to think that most fish handled in the manner above can potentially spawn and be available to another angler in the future. Taking care of the fish in this way is a great fit with our BVFF Angling Code.

I absolutely love what wilderness fly fishing adds to my enjoyment of life. I am so grateful for the wildlife resources we have to enjoy in Idaho. In return I want to appreciate the life involved and treat it well. Tight lines everyone!

It was a peaceful morning at 7,000 feet. The air was cool from the night before and the hot cup of coffee hit the spot. While enjoying the view over the lake something kept dropping on my head. At first I thought it was pine needles from the tree next to me, but then I saw black ants crawling on the bill of my hat. I shook them off and sat back down to finish my coffee, but more ants rained down and I decided to move further from the tree to avoid having to fish them out of my cuppa joe.

That afternoon while fishing the outlet of the lake I had Yellowstone Cutts come up and look at my flys (hoppers, caddis, and misc attractors) but no takers. Remembering the ant rain-storm from the morning I added a #16 black ant as a dropper to my hopper and BAM! First cast a cutthroat took the ant. I fished back through the water I had previously fish and had 6 more cutts come to the ant.

A good reminder, that it is that time of year when an ant pattern should be your go-to fly. Here is a “Bug Corner” article that ran in last year’s Hackle Bender newsletter.

FALL ANTS

When I look back at my September fishing logs I can’t help but notice how many fish have been caught on ants. Usually the ant was a dropper to a bigger fly like a hopper or an October caddis but instead of trout going for those BIG MAC MEALS they wanted the itty-bitty ant—and they often moved a long way to get them!

Ants are terrestrials so it is productive to fish them close to shore and especially near downed trees. Ant patterns are small and not very visible so they work well as a dropper to a larger fly. And it’s OK if they sink a bit because ants often get drowned and trout are on the lookout for them subsurface. In fact, sometimes a sunken ant will out-fish one on the surface.

I usually fish a black or cinnamon color ant in size #16 or #18 but some people swear by a size #20 ant. For years I used a traditional dubbed body ant with black hackle for legs but the last few years I’ve been using a foam-cylinder ant. They are easy to tie, float well and have a bright indicator built in that make them much more visible on the water. It’s also good to have some flying ants in your box as you never know when that hatch is going to happen, and Egan’s Bionic Ant is worth adding to your box.

Fly Patterns

Foam Cylinder Ant

Bionic Ant

January 6-7, 2023

For 18 years, Boise Valley Fly Fishers has proudly presented this two-day event. Over 2500 fly fishers from throughout the western region of the United States attend. Proceeds are used to support fly fishing education and conservation programs throughout Idaho and Eastern Oregon.

Exhibitors will showcase all the latest gear including the latest rods, reels, fly tying equipment, guide services, artwork and more.

Fly tyers from all over the west will demonstrate their skills in small group settings where attendees can ask questions and learn.

Experts from around the country will give demonstrate the latest fishing techniques for different fish species, where to fish, and much more.

More information: https://www.idahoflyfishingexpo.com

ID F&G recently held "Lets Go Fishing" day at Eagle Island State Park on May 28, 2022 as part of its Trailer Education program. The agency partnered with local radio stations for a ‘free fishing fiesta’ Memorial Day weekend to kick off the fishing season in Idaho. BVFF members Troy Pearse and Jon Fishback were there to provide casting instruction and information about BVFF.

Memorial Day marks the unofficial opener to fishing season in Idaho. This was a community event to introduce English and Spanish-speaking residents of southwest Idaho to fishing and recreational opportunities at the area’s state parks.