Delaware Reservoirs Starting to Fill

[Big_Spinner]

Hi guys,

The NYC reservoirs are starting to fill. This is important now since the new flow plan will increase releases throug the winter if reservoir levels improve.

On October 26th the reservoirs were at 60% of total storage. The rain storm we had the last few days have added 5% of total storage to the reservoirs. We are now at 65%

When the system goes above 75% storage, the releases go up.

The release amounts would then be based on the amount stored in each reservoir. Cannonsville would be a release of 110 cfs. This would be up from the current 80 cfs. When the reservoir then gets to 90% capacity, the release will increase to 250 cfs. Pepacton release will step up to 85 from the current 65 and then up to 185 when the storage in Pepacton goes above 90%.

At this time of year a storm with one inch of rain will add about 18 billion gallons to the reservoirs. 18 billion gallons is about a 7% increase in capacity. The amount into the reservoirs does depend on many other conditions, so this is an approximate number. This time of year the biggest offset from these numbers would be how much is NYC diverting to the city.

So, 2-3 inches of rain will be enough to bump up the release levels to numbers that would be more comfortable as we get into the coldest part of winter.

We continue to work on ways to improve this release plan and hope to make some changes before it is finalized for the next three years. "finalized" is certainly not the best word to use. Everyone involved with the FFMP is working to make the system more fexible and adaptive.

Suggestions and questions are always welcome.

Jim

 

[oasis man]

It is also interesting to note that yesterday the current total reservoir level was 3.2% above "normal", which I assume to mean average.
OM

 

[Big_Spinner]

Hi,

As of today (11/5) the reservoirs are at 66.4% capacity.

We are getting a bit of rain today, but not enough to bump the reservoirs to the next level of release.

River levels were staring to get low again, so the rain is welcome.

Lots of brown trout redds in the river. I did not get a chance to check any tribs this year.

Cannonsville gained 3 billion gallons of water since Friday. The other two reservoirs stayed about the same. This is mostly due to the diversions. No diversion from Cannonsville.

That's it for now,

Jim

 

[Big_Spinner]

Hi guys,

November 13th update of reservoir levels

The reservoirs have gained a few percent with only modest precipitation.

We are now at 67.6% capacity.

Cannonsville gained while the other two stayed about the same.

We are expecting a significant rainstorm over Wednesday-Thursday. Perhaps 1/4-3/4 of an inch of rain.

No that the leaves are gone, there will be more water entering the reservoirs from a rain storm.

This should get us over 70% and perhaps a bit more.

Jim

 

[NJFred]

Given current reservoir levels sure looks like the dams will be spilling on Spring of 2008 after the winter run off. That's good news.

 

[Future Fanatic]

Hi guys,

This should get us over 70% and perhaps a bit more.

Jim

I'm guessing, given the amount of water I see on the ground, that 70% is a lock, and 75-80% is likely. I'm seeing sheet flow. Watch the discharge for the WB at Walton.

 

[Big_Spinner]

Hi Future,

I think you are exactly right.

This rain should bump us up to at least the 75% level.

If things get cold enough it may delay some of the runoff, but we should get there.

Jim

 

[Future Fanatic]

Hi Future,

I think you are exactly right.

This rain should bump us up to at least the 75% level.

If things get cold enough it may delay some of the runoff, but we should get there.

Jim

Well, it is essentially 75% right now... Do I hear 80%?... 85%?....

 

[Big_Spinner]

Hi Guys,

Here is a bit of a clarification. The FFMP is concerned with the three reservoirs in the Delaware System. (Pepacton, Cannonsville and Neversink)

This link shows a more complete NYC water supply system. Its current level is 74.3% while the three Delaware Revervoirs are at 68.3% as of Nov. 15th.

Current Reservoir Levels

So, we need the three Delaware reservoir total storage to reach 75% capacity (Total capacity is 270.8 Bg) in order to get to the next level of release. This should happen in the next few days. This rainstorm has dropped enough precipitation to do it, there is just a bit of travel time.

Rain is supposed to turn to snow later today!!!

Jim

 

[Big_Spinner]

Hi guys,

The rainstorm delivered substantially more precip than was anticipated. We received about 1.5 inches in Balls Eddy.

This will translate into getting us to "spill mitigation" level for the reservoirs.

Here is how simple the new system is:

What is the date? Nov 16

What is the Combined Storage of the 3 reservoirs? 69%

Read the level from the graph: Nov 16th and 68% equals Level 2.

Look at the table to determine the release level for each reservoir.

Cannonsville = 80 cfs minimum release
Pepacton = 65 cfs minimum release
Neversink = 45 cfs minimum release

What could be simpler?

Now, there can be disagreements about the amount of water released at any particular level, but it is easy to determine what the minimum amount of water released will be.

Next week when we go above 75% capacity for total storage, there will be one more step involved in determining the release from each reservoir. When total storage exceeds 75% this time of year, we enter "spill mitigation" level.

Jim

 

[Big_Spinner]

Hey guys,

We hit 70% of total storage today and should be at 75% by Monday.

Have a good weekend,

Jim

 

[Big_Spinner]

Hi,

Closing in on "Spill Mitigation Level" (75% total capacity)

We got to 72.6% today (Monday) as of the midafternoon report.

Streams are still running well and we got about a quarter inch of water today. Mostly snow, but it is melting. Looks like more precip this week.

Jim

 

[Big_Spinner]

Hi guys,

Here is the website to see what predicted flows and reservoir levels will be:

Advanced Hydrologic Prediction Service: Binghamton

Jim

 

[Future Fanatic]

Hi,

Closing in on "Spill Mitigation Level" (75% total capacity)

We got to 72.6% today (Monday) as of the midafternoon report.

Streams are still running well and we got about a quarter inch of water today. Mostly snow, but it is melting. Looks like more precip this week.

Jim

73% as of Tuesday...
The Upper East is still flowing pretty well.
The Upper West is still flowing VERY well.
75% by Friday or Saturday?

So will the 30cfs increase mean much to the West Branch?

 

[Future Fanatic]

73% as of Tuesday...
The Upper East is still flowing pretty well.
The Upper West is still flowing VERY well.
75% by Friday or Saturday?

So will the 30cfs increase mean much to the West Branch?

73.86% on Wednesday...

 

[Big_Spinner]

Hi Future,

Have a great Thanksgiving!! Same goes to all!!

The old winter release on the West Branch was a 45 cfs minimum under FFMP we get 80 cfs until we get to 75% total reservoir capacity.

Then we bump up to 110 cfs, or the extra 30 cfs you mentioned.

Every bit is going to help when the really cold weather arrives. So, 30 more will help, but you are right, I do not think it will be a huge benefit.

We are poised though to keep adding storage to the reservoirs and when an individual reservoir goes above 90% capacity, that reservoir will jump up to the next release level. That is a release of 250 on the West Branch. That would really help during a cold snap.

Last winter we were in the upper level of release for a long time and we had a release of 1000 cfs for much of the winter. This meant no anchor ice at all on the river. Under FFMP that level is now 1500. Really more than the river needs, but does give a minor benefit for flood mitigation.

Flow at Walton is well over 1000 cfs, so there is lots of water still going into the reservoirs.

This is of course where the flood groups differ in what we want. Flood groups would prefer the reservoirs never get near full. Releasing more water now would help both everyone, without risk to NYC.

Have a great Thanksgiving!!!

Jim

 

[Future Fanatic]

76.23% today.
Upper East and West Branches flowing very well (again) after this rain throughout the day today, too.

Jim, do you happen to know(or anyone for that matter) how the levels within the reservoirs typically fare during the winter? I mean, is there a pattern as to whether they fall steadily through the winter up until the spring thaw or is it less predictable than that?

 

[Big_Spinner]

Hi,

Todays total is 78.6% for the Delaware Reservoirs.

Spill mitiagation releases have begun.

Individual reservoir levels determine the spill mitigation release from each reservoir. Today's reservoir levels:

Cannonsville: 78.8%
Pepacton: 76.6%
Neversink: 85.3%

The next level of release will kick in as each reservoir reaches the 90% level.

Jim

 

[Big_Spinner]

Hi,

Tuesday Dec 4th

Cannonsville release is 110 cfs.

Cannonsville Reservoir is at about 84% capacity.

We should reach the 90% level soon. This will dictate a release of 250 cfs from the reservoir. That will be a nice winter release for the West Branch. A huge improvement from previous regimes of 45 cfs through the winter.

Jim

 

[Big_Spinner]

Hi,

Cannonsville is at about 87% capacity and Neversink is at 88.4% capacity.

Cannonsville is still going up and Neversink and Pepacton have started to level off.

3 Bg more water in Cannonsville and the release will increase from 110 cfs to 250 cfs.

It looks like the sloppy weather we have coming next week will get us over the 90% level and initiate the higher release.

Snowpack is also going to be measured. Half of the measured snowpack will be added to the reservoir for calculation purposes. In fact, it may be that the small snow pack we have has already initiated the somewhat higher release. Hale Eddy gauge jumped more than I expected today.

We still need to get Stilesville gauge on line and real time so we can see what the release actually is!!

Jim

 

[Big_Spinner]

Hi Guys,

This is the latest from Cannonsville Reservoir.

88.5% full. I drove through Walton today and it realy is close to full. About 6 feet down from the crest.

Advanced Hydrologic Prediction Service: Binghamton: West Branch Delaware River at Cannonsville Reservoir

Not quite sure how the measured value drops significantly instantly. Seems like it might be NYC "recalibrating" their gauge.

Time to check out operations.

Remember, when Cannonsville hits 90% the relesae goes up to 250 cfs.

Jim

 

[AKSkim]

Just wondering if it is due to ice expansion?

I would be very cautious with your enthusiasm when it does reach 90%, trouble might be when it reaches 103%, 114%, 127%.

I would suspect the people down stream interest in the trout habitat may just ween a tad.

Hey, what do I know.. I live up on a side of a mountain.. so far no avalanches.

As always, not one to take my surf board to a river.

AK Skim

 

[Big_Spinner]

Hi,

Cannonsville is at 90.3% capacity so the release should be 250 cfs.

This should be good for the river as we enter a relative cold snap the next few days.

Jim

 

[Big_Spinner]

Hi,

Looks like the release of 250 has started as advertised.

http://waterdata.usgs.gov/ny/nwis/u...01426500&set_logscale_y=1&begin_date=20071206

So far, the rivermaster, who is now in charge of FFMP releases, has been right on as far as making the releases when they should start.

It still would be nice to have the Stilesville gauge available in real time so we can see what the releases are going to be.

Jim

 

[Future Fanatic]

Just wondering if it is due to ice expansion?

Ice only expands about 10% over the volume of liquid water. I doubt there is much ice on the reservoirs at all(yet). But even if there were two inches, that's only 2/10 of an inch of displacement to account for. Interesting idea though. I wonder if the Water Lords ever had it cross their minds.

 

[Future Fanatic]

Looks like the release of 250 has started as advertised.

So far, the rivermaster, who is now in charge of FFMP releases, has been right on as far as making the releases when they should start.

Jim

Looks like after today and what is forecast for Sunday, they'll be entering much more snow pack into the equation.

 

[Big_Spinner]

Hi,

Reservoir predictions are to start leveling off. The cold weather will store the precipitation as snowpack.

Here is where the reservoir levels will be only part of the equation.

The snowpack calculation is not available on line so it will be difficult to know where we are as far as releases are concerned.

We are working with the decree parties to make this information publicly available in the near future. I know that NYC DEP has some automatic snowpack instruments and also uses manual measurements.

Cannonsville is about 92 - 93%. Total storage is calculated by dding half of the snowpack to the actual toatl in the reservoir.

The release today is 250 cfs. The reservoir is above 90% and below 95%, so according to the FFMP table, the release is 250.

When half the snowpack is added in and the total "storage" exceeds 95%, the release increases to 1500 cfs. Quite a jump, but this is not a concern as it happens naturally all the time. There is a bit of a concern on my part at the other end. When we drop below 95% and the release drops from 1500 to 250, that is not natural. FFMP does have a ramping protocol to make this drop happen over 3 days, instead of near instantly, like in past years.

Jim

 

[AKSkim]

Cannonsville is about 92 - 93%. Total storage is calculated by dding half of the snowpack to the actual toatl in the reservoir.
Jim

Well, if you go by someone else's comments... "10% over the volume of liquid water..."

I guess that would equal 102-103% right about now.

As always, seeing things other's fail to see.

AK Skim

 

[Big_Spinner]

Hi Skim,

Say what?

 

[Future Fanatic]

Well, if you go by someone else's comments... "10% over the volume of liquid water..."

I guess that would equal 102-103% right about now.

As always, seeing things other's fail to see.

AK Skim

Hey AK,
There shouldn't even be ice covering Cannonsville yet. It should still be open, save some of the shallower ends. Don't you KNOW these things? AND, it would be 10% greater than the volume of water that was frozen... oh nevermind. (hey, quit it with the apostrophes, too.)