Dangers of Lake Hopatcong 5-Foot Drawdown

  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

I know its hard to think of right now, but as high as the water is right now, next year may not ever recover from the 5 foot drawdown, and here's why.

By: John Kurzman

When the plan was modified last, the roadmap was that the 5 foot recovery plan would be updated before the next one, but that was not done, and the DEP now is not willing to do so.

a) So although the annual plans only used to draw down 26 inches, and most recently the plan has been to draw down 22 inches, the 5 foot drawdown will only attempt to refill the lake to 30 inches from dam top, and then stop! In other words, we are guaranteed to be 4 inches worse than we've been for 10+ years of drawdowns to 26 inches, and 8 inches worse than recent years. Remember, we now do 22 inch drawdowns because there is concern that it is tough to expect a refill of more than 22 inches in the springtime, even 26 inches of refill has been too much to expect, but next year, we would require 30 inches!

b) But its actually much worse than that. The refill from 60 inches down to the 30 inches (which should be 22 inches as per above), actually has a very slim chance of happening anyway. This is because unlike past 5 foot drawdowns, the DEP has indicated that they will not be willing to let the ice rise, even in the range of 60inches down to 30inches down, as has been done in past 60inch drawdowns. So if the ice freezes between December 15th, when the refill from 5 feet down starts and the springtime, all that time will let the refill water go out to the Musconetcong, and they will hold the lake level constant.

c) This is NOT how it was done in the past. Even 5 years ago, we have documentation that the ice was more than 14 inches thick and the USGS gauges clearly show that the DEP released only 12cfs all winter during even that thick ice time until the moment the lake hit 30 inches below dam top. Only then did the DEP start releasing more water and keeping the lake constant. That is what we would want done this year again, but the DEP has said they will not do that, and they denied that they had done it last time, but the gauges confirm it. Also, it is on the LHC record that nobody complained of any damage from the ice rising from 60 inches down to 30 inches down. Note that there are far fewer structures even in the water when the lake is drained that far down. If you look at the first attachment, you can see how the ice was allowed to rise until the lake hit 30" down, and then outflow was increased.

It would be nice if we could even try letting the ice rise to the 26 inch down or 22 inch down that was going to be discussed at a later CAC meeting (item a above), but at a minimum, we must let the ice rise as in all the past 5 foot drawdowns before, including the last one, or really, the lake will not just be 4 or 8 inches behind, but could be feet behind in recovery when the springtime hits if they stop the refill from 5 feet when ice hits.

If you look at the second attachment, you can see, based on past years, what probability of inches the lake could rise each month. Note that the bottom half shows AFTER 3.6 inches are lost each month due to 12cfs. Since outflow is to help make sure the downstream fish do not get too HOT, in the midst of winter, there is no question that 8cfs (ie. 1.2 inches gained per month) would be reasonable, and there is data that shows significantly less has been outflowed during those times without any ill effects to downstream. The upper chart shows the possible inflow probabilities without any outflows, but even that shows a serious problem if Ice is not allowed to rise and we stop refill 30 inches below dam top (require 30 inches in springtime), which we already know is unreasonable, andwhy we switched to 22 inches, and these charts confirm that.

Lake Hopatcong Draw DownChart 2

If you look at the 75% column in that 2nd photo attachment, it means only 25% of the years do worse, we would get almost 40 inches December-March 30 considering we wait until mid-December to start refill, even with 12cfs. So that in itself is not the issue, and 5 foot drawdowns, on their own merits, IF YOU LET THE ICE RISE FROM 5 FEET to 30 inches, is not the problem. But b) they are not going to let the ice rise, so it is a problem because we will need much more than 30 inches in the spring if there's ice at all this winter. And a) April thru June, 1/2 the years get us less than 26.9 inches, and 1/4 of the years would get us only 15 inches if its a dry year, yet the lake will need at least 30 inches, and probably more if there was ice during the winter. The best 1/4 of the years though, April-June, would get us 58 inches, but if we believed we could rely on that, we wouldn't have needed to switch from 30 inch drawdowns to 22 inch drawdowns!

So the lake will be AT LEAST 8 inches lower going into springtime than normal, probably much more due to ice. My feeling is that if they don't fix the refill, they probably shouldn't do the drawdown, but the LHC says it is not up to them to even make that decision any more. (They worked hard on this, wrote multiple letters, fed Steinbaum provided a proposal, I went to Trenton and presented these slides previously to encourage the plan changes, etc, but the plan is not changing in this regard currently). I also gave the name of another contact at the DEP who might be able to help to Ray Fernandez who was going to try to setup a meeting with them and Marty Kane to try to help resolve, as of the last LHC meeting, but I have not heard anything since.

Given that the LHC still is our official voice, this coming Monday's meeting at Jefferson boe building 7pm may still be the only way to get the message that something needs to be done.

I believe 5 foot drawdowns are important to the lake, but not if the refills are not even going to have the same likelihood of success as past years. At this point, the best thing we can ask for is that they let the ice rise until the 30 inch below dam mark, like they did 5 years ago and many years in the past, or even potentially higher pending any complaints. But otherwise, if they can't do a reasonable refill, people need to recognize the likelihood of refill is extremely slim, and plan accordingly or other actions.

Join us on Facebook

Upcoming Events