Tulpehocken Creek

[VTPAangler]

I attempted to fish the Tully this afternoon only to find a wasteland when I arrived streamside. I didn't have a thermometer, but would guess the water was pushing 80 degrees. The tributary that runs in at Paper Mill Rd. and Tulpehocken Rd. was running in the high 60s I'd guess. There were a few trout holding at the confluence, though far fewer than I anticipated. The Tully itself looked awful, and I never took a cast. This was my first trip to the Tully in midsummer. I've always been under the impression that this river maintains cool water temps throughout the summer because its a tailwater. I was quite disappointed to find the stream in the shape its in, and I can't imagine fish responding to a trico hatch there right now. Can you guys (or gals) with experience on the Tully tell me if what I experienced today was typical? It's hard to find a viable stream in Southeastern PA during midsummer. I guess I'll have to stick with the Little Lehigh and Valley Creek.

 

[Mike]

A quick check of the USGS web site for real time data indicated that the Tully's temperature at the waterworks started out at about 68 deg at 8 AM and peaked this PM at 72 deg. Sixty-eight degrees is the 8 AM objective for fish management and cold water conservation. This is exactly how the releases are designed to function in order to conserve the cold water below the lake's thermocline as far through the summer as possible as well as only on occasion allowing the water temp to hit 75 or 76 deg. in the afternoon on the hottest days. The cold water is usually depleted between July 22 and July 28. If the stream were kept colder through June and July, the cold water in the reservoir would be depleted even sooner and less fish would survive the summer. Experimentation with temperature objectives for the tailwater was conducted in the early 1980's by the Corps dam operator and me.

One change that occurred today is that the Corps of Engineers apparently needed to lower the flow below the 120 cfs objective (for the trout population and habitat) to 90 cfs, which still is not a bad flow given the present flow conditions around the southeastern part of the state. The Corps minimum objective is around 50 cfs, but under sever droughts, flow has gone even lower.

 

[sight_nymph_17109]

VTP,
I've had similar experiences in the past on the Tully. I'd love to fish the trico hatch but I feel like the fish are struggling just to survive. My rods have been collecting dust since the begining of June. I'm not too interested in bumping elbows with everyone where there actually IS some cold water flowing. The golf clubs are getting a good workout now. I hope to hit a spring creek before the end of the month but I'll probably wait another week or so and just head up to the West Branch where the water's flowing in the low 50's. I don't care what anyone claims, the Tully (among other streams that are supposed to be "cold water" fisheries) are marginal when it comes to temps. Good luck on the LL.

 

[VTPAangler]

Thanks for the info. I have to say that the water was most definitely warmer than 72 degrees at 3:30 PM. No question about it. Some rain would provide a needed shot in the arm.

 

[Mike]

Blue Marsh Reservior is managed in order of priorities, which were established probably as the reservoir was being authorized for construction. Those priorities are flood control, water quality management in the Delaware Estuary (salt line management), water supply, and a distant last...recreation, including fish(ing). I may have reversed the middle two priorities, but I don't believe so. Any water level (in the lake) and release manipulations or proposals related to water levels and releases have to be designed to fall within the requirements established to meet the first three priorities. It is easy for anglers to think only about the fish and fishing, but fisheries managers have substantial limitations that they live with in multiple use reservoirs, and these limitations often lead to less than ideal fisheries management. A wise Fisheries Director once said; "if you can't accept (or work within the limits established by) political realities, then you shouldn't be a fisheries manager." Regarding the management of Blue Marsh lake and the Tulpehocken, the Corps has been quite cooperative in considering PFBC, TU, and BASS proposals and in working to help improve the fisheries within the operational limits of the reservior.

 

[sight_nymph_17109]

Mike,

I'm not singling out anyone in particular for the stream flows or temps. I realize that the impoundments in the state were built for the purpose of flood control. All I'm saying is... if it isn't going to be managed like a cold water fishery, it shouldn't be promoted as one. Why waste the money and time until the PFC and Corps come together on a water release program? Use the license $$ to restore or aquire land rights on other streams. I wish that the state would have built the dam near Lickdale on the Swatara Crk. Then, water flow and temp issues could have been addressed right from the start. I just take the Tully for what it is and don't usually fish it unless the morning temp is 68 or lower. Just curious, who do you work for? If you have connections, can you talk to someone about the wasted cold water fishery below Raystown?

 

[MattBoyer]

sight_nymph_17109 wrote:
I wish that the state would have built the dam near Lickdale on the Swatara Crk. Then, water flow and temp issues could have been addressed right from the start.

The Swatty was in the upper 70's today behind my house, 13 miles upstream from where the Swatara Dam was to be built. I can't believe that damming this creek up would have in any way, shape or form imroved this fishery. It would've turned a few wild trout streams into part of a warm water lake, but still would've been full of warm mediocre quality water. The only people who would have benefited from this dam would've been the people connected to the original planning commission who bought up adjacent land while families who lived there for generations were forced out by eminent domain. The days of building a dams based on political constituancy are over, thank God, and there are no valid reasons to return to those days. I have friends who lost farms that their great-grandfathers built because of this project and have a bit of a bitter taste in my mouth for the whole thing. I hunt on what would be lake bed and appreciate the history of the Union Canal, all of which would have been lost to this porrly planned lake. Add to that several unique fossil beds in and around the park and it's a no- brainer. Besides all that, it's carp fishing season anyhow. :-D

Boyer

 

[afishinado]

Here is the Tully temperature reading for the last 31 days at the Waterworks, a mile or so below the dam. As Mike said, the temperature hasn’t exceeded 72* as of yet.

http://waterdata.usgs.gov/pa/nwis/uv?cb_00060=on&cb_00065=on&cb_00010=on&format=gif_default&period=31&site_no=01470960

This is the temperature reading above the dam at Bernville. The peak temperature is 1-2* F higher, but the fluctuation is greater since it is more a reflection of the highs and lows of the air temperature.

http://waterdata.usgs.gov/pa/nwis/uv?cb_00060=on&cb_00065=on&cb_00010=on&format=gif_default&period=31&site_no=01470779

As Mike said, Blue Marsh is not a deep lake (50+/- feet deep) and doesn’t hold a large pool of cold water. I don’t think any flow plan would change the results much, even if the number on priority WAS recreation.

I watch the flows and temperatures all the time. In July and August the Tully is nearly always too warm to fish. Some of the trout seem to survive the higher temperatures through the summer, and Cacoosing Creek usually lowers the temperature a bit, but the trout are in the survival mode at this time of year.

Sight nymph - maybe Mike can answer this, but other than stocking, I’m not sure that any extra money is being spent on the Tully by the PFBC. To me, stocking the Tully is money well spent, since most other stocked streams are fished only for a couple weeks a year, while the Tully provides recreation for 9-10 months a year. It’s very far from perfect, but I’m not sure what can be done to improve it short of raising the dam and increasing the capacity. I would not be in favor of that. Just my opinion.

PS - Sight nymph - Mike is the PFBC fisheries biologist for the SE region.

 

[LehighRegular]

Intersting dialog....

I have a few things to add to it all and some questions for Mike

Let me first say, that Blue Marsh is very limited with the amount of coldwater that can be stored in the lake. If the lake was not there the water would likely be warmer than it is today in this stretch of water and basically trout survival would be nill. That said, can the Corps do some additional things to tweek how they manage the reservoir to help the fishery. IMO, I think they can albiet "minor".

I have worked with the Philly Dist of the Corps for 3-4 years re: the Lehigh/FEW reservoir and let me say the Corps has a very limited knowledge on how to manage their reservoirs tailwater fisheries. I'm not bashing them and honestly its not their job entirely nor or they trained to do it. The Corps takes direction from the PFBC regarding these matters. And look how many "GREAT" tailwater fisheries we have in PA. By great, I mean destination type fisheries with large populations of large wild trout. We have the impoundments in the state to do it, but somewhere the intiative to enhance these fisheries is lost.

My questions for Mike: (You don't think I'd let you off the hook that easy :-D )

The cold water is usually depleted between July 22 and July 28. If the stream were kept colder through June and July, the cold water in the reservoir would be depleted even sooner and less fish would survive the summer. Experimentation with temperature objectives for the tailwater was conducted in the early 1980's by the Corps dam operator and me.

What was the outcome of these experiments?? I have never seen anything published re: this work. Is there anything you can provide??

Depletion of the coldwater or "cooler" water in BM is really dependent on rainfall. But largely, the coldwater pool is as Mike said depleted by August, esp in dry years. The big question, is there a way to sustain the pool longer??

And I don't think tweeking the valves to release the coldest water from BM to cool the stream for a late June trout stocking event this season helped to "sustain" the coldwater pool.

One change that occurred today is that the Corps of Engineers apparently needed to lower the flow below the 120 cfs objective (for the trout population and habitat) to 90 cfs, which still is not a bad flow given the present flow conditions around the southeastern part of the state. The Corps minimum objective is around 50 cfs, but under sever droughts, flow has gone even lower.

The Corps drops the release below 120 cfs all the time. This is nothing new. The release is completely dependent on inflow to maintain the pool elevation (290ft) in the lake. If that were the case and the Corps was "required" to meet the 120 cfs objective for trout population and habitat, the lake pool elevation would fluctuate more so and at times drop below the 290ft elevation designation. So basically this "objective" is worthless and doesnt mean a thing. If that "objective" could be met within certain confines of BM operations, that would do wonders for the stream, esp during this time of year.

Look forward to your reply. :lol:

 

[Chaz]

Do we know what would happen if they raised the eleveation of the reservoir 5 feet? 10 feet? I don't think so. But one thing in all of these stories of tailwaters in the Delaware basis is the salt line. I don't think that DRBC even considers that by having more water to release all summer from all the reservoirs would keep the salt line well below Philly's intakes, but I beleieve that is what would happen. If it would go like that they'd never have to worry about making huge releases to keep the salt line down, it would already be down.
We could have at least 4 great tailwater fisheries in eastern PA, Lehigh, Delaware, Tully and Tohickon.

 

[sight_nymph_17109]

I agree w/ Chaz. Raising the water level in the lake can't hurt.

One question for Mike... Even if the dams weren't built with trout fishing in mind... why are there great tailwaters all over the country but not so many here? Is it a difference in the way the cold water supply is managed between Corps and the states?

Examples:
Green River, UT
White River, AR
Bighorn, MT

 

[LehighRegular]

Guys

For starters the Corps just can't raise the water level significantly in BM. I think the major reason is that there are a number of boat launches and recreation areas that would be inundated if the water level was raised 5 feet or more.

2nd thing is how would that cut into flood control capabilities because that operation trumps everything else.

3rd, would be boating concerns I would assume.

Question would be how much flexibility the Corps has in the Lake level...is it one foot, two feet, plus/minus the normal pool elevation??

Chaz...You forgot two other tailwaters, Beltzville and Wallenpaupak...so make it 6 in Eastern PA.

SlightNymph....the western tailwater fisheries are created behind HUGE and I mean HUGE reservoirs. Ones that dwarf the Upper Deleware Reservoirs. So the West has a lot more coldwater to draw from and for the most part are never worried about running out of coldwater. If I'm not mistaken, Lake Powell (23.5 million acre feet) on the Colorado is approximately 7 trillion gallons when filled to capacity....(but my math could be wrong when I converted acre feet to gallons? - But that would seem about right). Cannonsville (West Branch of Upper D) is only about 100 billion Gallons. Pepacton is about 140 billion gallons.

So the biggest thing out west is there is no worries about running out of coldwater.

 

[JackM]

Add to the sheer size of those mentioned reservoirs the likelihood that the water coming into and therefore flowing out of them is more conducive to trout and forage. There are factors other than water temps that effect the ecosystem.

 

[Mike]

Lehigh Regular and others:

The experiments were really operational adjustments aimed at fine tuning the releases to extend the cool discharge as far into the summer as possible. Experiment, in the strictest sense, was the wrong choice of words. The first year the discharge was just run from the bottom for the entire spring as I recall. Obviously, based upon what we now know, that was a loser from the get-go. The next year we tried something like maintaining the tail-race (USGS station) at 64 deg F. That did not work either. Again we ran out of cold water in late spring or early summer. I believe it was in the third year that we experimented with maintaining the 8 AM temperature in the tail-race at 68 deg F. In the third or fourth year we also tweaked it by saying it should be 68 deg F at 8 AM for three days in a row before any bottom discharges begin. That avoided doing a bottom release just in response to the first spring warm spells. This is how temps have been managed since that time. It was noticed during the "experimental" period that if water temps in the tail-race were 68 deg F in the morning, then the water temp only occasionally rose to 75-76deg F on the hottest afternoons and evenings. This would likely stress trout, but not kill them. This conserved cool water farther into late July. I would add that this temperature regulation is discarded when storms dump enough water in the basin that the lake rises and the Corps needs to release more high volumes to bring the lake down to the 290 ft summer elevation, quickly reestablishing the flood control capacities. Cool water is often lost at such times.

As for the 120 cfs objective, I think the Corps did a good job of maintaining that objective during some difficult inflow periods through June of 2007. I can assure you that there was some extra attention shown toward tailrace flows.

As for lowering the stream temperature to improve the survival chances of the trout that were stocked in 92 deg weather on June 28 by adjusting the discharge, I would recommend that under similar circumstances again, even though it was not my idea. I worked well under the circumstances that we were facing on that day. Despite your concern about lost cool water volume, that assured survival at the time of stocking until the cooler weather came the next day. Furthermore, anglers on this very board had been complaining about crowded conditions in the DH Area, especially during the late June trico hatch. Fly anglers took advantage of that fresh stocking below the DH Area in the covered bridge bend,etc and even below Grings Mill Dam. Fly anglers and bait anglers were beneficiaries of the stocking. Additionally, we are equal opportunity fisheries managers. If you had seen the kids who had likely ridden their bikes from Reading to fish for the freshly stocked trout at the Grings Mill Dam you might have thought that perhaps releasing the cool water had been a good idea.

 

[LehighRegular]

Mike

Interesting experiments I must say and it appears you and the Corps are doing everything possible to extend the coldwater pool. I'm also not that familar with the tower set up and volume of water each gate can discharge.

As for your 120 cfs "objective", I'm not entirely on board with your explaination. I guess I may have to follow it closer to get a better understanding of the operation and keep you on your toes :lol: I also beleive that the Corps gives "extra attention" to the flows but in your opinion could there be anything more done in the way the Corps releases the water to sustain this coldwater pool? Is there any flexibility in reservoir operations as it pertains to the lake elevation?

As for the June 28 release - I will concede that for the kids. If that be the case, then it was well worth it.

 

[jhguster23]

By far, the best, most consistent tailwater fishery in our area is the Gunpowder River in Maryland. It is literally too cold to wet wade, and I fished it in the heat last weekend. Morning water temps are often in the low 40's. When the sun starts to come up and the air starts to warm, steam rises off the water.

I'm not sure what differs in the management practices between the two streams, but I have fished both, and the dam at the top of the Gunpowder appears to be a lot higher than the one below Blue Marsh Lake. Presumably, the release is from deeper, colder water.

The one major drawback of the Gunpowder during the summer is that they do not release a lot of water, and the water that they do release is as clear as gin, so the fish are extremely spooky. For those of you who are devoted Tully fishermen but worry about the warm water temps, the Gunpowder is the place to go.

 

[Mike]

LR asked: I also beleive that the Corps gives "extra attention" to the flows but in your opinion could there be anything more done in the way the Corps releases the water to sustain this coldwater pool? Is there any flexibility in reservoir operations as it pertains to the lake elevation?

Reservoir elevation flexibility is very, very, very limited. As for operational changes, all would have to fit within the limitations established for other higher priority uses. One problem, purely from a discharge standpoint, is that the higher level gate has a capacity to release about 300 cfs as I recall. If water needs to be released following a substantial storm (to bring water level back down to summer pool elevation) and the flow required to bring the lake down quickly is over 300 cfs, then the bottom gate is opened to release the extra amount. This results in a necessary, but unfortunate, release of cold water at times.

 

[LehighRegular]

Mike
Thanks for the info. The tower set up is an unfortunate situation.
LR