River Flows
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Author:  Jeff Reardon [ May 14th, 2017, 9:21 am ]
Post subject:  Re: River Flows

granger wrote:

I hold you in very high regard, but Have you "jumped" to this conclusion about Brookfield's water storage policies or is this backed by some detailed analysis? I mean we had a lot of rain in May on top of a water dense snow pack, of course the lakes are full. Imagine what the Androscoggins flows would be right now if 16,500 acre Mooselookmeguntic was not holding back it's full storage capacity of 198,000 acre feet of water? The previous year, did we even have a winter? Mooselook never really filled.

Are you sure your conclusion is sound? I have seen the Lake Level time series graphs on Mooselook. Longterm Averge vs Annual data for Brookfield. Didn't seem too bad. Don't know about the other lakes with Brookfield dams..


Tom--not detailed analysis, but a pretty careful look at a snapshot in time--early May in 2017, comparing (1) Lake levels in the Rangeley area compared to long term averages; and (2) River flows at sites with USGS gages compared to long term averages.

To add to what I posted above about river flows, here are some lake level comparisons. (Note, the long term average lake levels I am using here come from the late 90's relicensing of Upper and Middle Dams (which is why I only have them for Richardson and Mooselook). If I remember correctly, those averages were based on about 40 years of data ending around 1994.

In a median year, on May 1 Mooselook would have been at about 1463.5; Richardson at 1444.5. Union Water Power would have been filling the lakes aggressively in early May, targeting full pond sometime between May 15 and June 1, depending on spring rain fall.

In 2017, on May 1 Mooselook was at 1467.6 and Richardson at 1449.1--both essentially full pond. That's a pretty big difference. And it's a difference taht matters, because it means there is no room to store any rainfall that comes after the lakes are full. How many years do we get through May and June without a series of pretty rain storms--like the one we are having today? If the lakes are full at the start of May, all of that water has to be moved.

Maybe it just reflects a wet spring this year--and it has been kind of wet--or maybe it's a different management philosophy. So I looked back at the last several years. Last year on April 29th--I was off fishing in early May and not checking Waterline :D --Richardson was at 1449.61; Mooselook 1466.51. Again, approaching full in early May, with both lakes 3-5 feet above where they had been during the "historic" 1950's-90's period on the same date.

In 2015 the May 1 levels were just about normal--but it was a pretty dry spring, with all of Maine's lakes filling pretty slowly Richardson and Mooselook didn't fill until around June 1.

So, yes, it's based on some data analysis, but a lot more could be done for a forensic analysis of flow management. Any a number of things could explain these differences--climate change may be shifting snowmelt (and therefore the refill date for lakes) earlier; spring rain patterns may be different (and some climate change models suggest more frequent and intense spring/summer rain events); and of course the "average" year never happens, so what we saw in 2016 and 2017 may just be normal variation.

The last thing I'd say is NOT based on any analysis, but is an observation that I think could be analyzed. My sense is that in the past, common practice, especially in wetter years when refill occurred early, was to hold Richardson and Mooselook a foot or so below full pond to allow for spring rains to be somewhat controlled. This was a gamble--if May and June turned dry, you could end up starting the summer with the lakes a little low. But Union Water Power balanced that against being able to avoid dumping water if spring rains came.

My sense--and it is only a sense, not an evaluation--is that in recent years we have seen more emphasis on refilling the reservoirs as early and as full as possible. I think I see this in flow releases in May and June. In the "old days" it was pretty common to see Rapid River flows of 800-1200 cfs in the May/June period. That issue could use more analysis-which I have not done. The data to do that work are reported to DEP and could be requested.

Author:  granger [ May 15th, 2017, 5:51 pm ]
Post subject:  Re: River Flows


Great response. Thank you for taking the time to share your thoughts on this in such detail. Appreciate the work you do for the State of Maine.


Author:  Jeff Reardon [ May 17th, 2017, 9:54 pm ]
Post subject:  Re: River Flows

Just to note, the recent rain immediately drove releases below many of the storage dams in the state--all the Androscoggin reservoirs and Flagstaff, at least--to near flood levels. Full pond and 1.5-2 inches of rain means they've got to dump that water.

Based on the standing water in my backyard when trying to mow the lawn yesterday, I'd say there is still some run off to go from this event.

I'm glad I prefer fishing ponds and small streams this time of year.

Author:  Hunter [ May 18th, 2017, 11:10 am ]
Post subject:  Re: River Flows

River flows are coming down fairly quickly, now that the leaves are popping and the trees, grass, etc... are starting to suck up water and transpirate. If memory serves me right- Shawmut was generally not really fishable in the "good" days until after the 3rd week of May. I'm hoping to float it after it drops below 11K, which I'm anticipating will be one evening next week- baring any significant rain in the forecast (and at this point- it will take more than a 1/2 inch of rain to bump things).

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