Will's River Correlations for NE

Ash and Otter Brook correlation

I thank Andy Gordon and Tom McIntire for putting me onto this. Regarding the Ash, Andy says the "West Swanzey gage is a good indicator as to what the lower section is doing". However I like the upper more and was looking for ways to tell if it was up. Tom says you can use the Ball Mountain data to estimate the upper section of the West river at LondonDerry. Turns out this is true for the Upper Ash and Otter Brook as outlined below. You want to look at the dam's inflow for the flow in the portion of the river above the flood control dam.

Sadly the Army Corps seems to change these every year. I haven't figured out why, who can predict what a web page developer will think is cool. It changed in April of 2004 and again sometime late in 2007. I tried to access the pages in Oct 2009 and found they had changed yet again. Due to a post and email from Alan Darling I think I have it working again. See below for current Top Level and direct access URLs.

Start at the top level URL for Army Corps flood control data sites of the Connecticut River Shed. Near the top is a list of Topics, putting the mouse on the the tab to the far left, 'Hydro Data', should give you a drop down list. Select 'Real Time Data Map', the first entry in the list.
After the map is displayed, click on VT (top lefthand region of map) to select it. Allow the new detailed map to display. Now you can click on any of the icons on this map to get the real time data for that location.

The DAMS of interest for the upper sections of Ash and Otter brook are the SMD (Surry Mountain Dam) and OBD (Otter Brook Dam) in the VT region. With a little fumbling around I figured out the direct links below, but it might change again. If it does change again try going back to the top level.

My correlation is based on "Real Time Tabular Data" for the dam of interest. This has a column for 'inflow' which is the data of interest. This seems to be a good predictor of the hand painted gage levels although it may be derived from the outflow and rate of change in pond level.

For the Upper Ash, go to SMD Note there is now also an on-line gage station available on the upper Ash near Gilsum, GIL icon on the image map. The old gage has been given new life, at least temporarily. The CFS it reports seems slightly lower than the SMD inflow which my correlations are based on, but time will tell and USGS will probably keep adjusting it as its just provisional now. Of interest the real time data also shows water temperature!

For the Upper Otter, go to OBD

After the previous build up, I currently only have a few correlation points. All the Otter brook observations are consistent. For the Ash the high CFS and the this years data for 500 CFS and below are consistent. However I went to the Ash on 3/28/02 thinking it would be above 4.5 based on my (currently suspect) 3/13/00 observation and was disappointed. This may just mean the inflow estimate isn't that accurate. I currently think the Ash is questionable below 500 cfs.

Date       time     inflow (CFS)   observed gage
                                   Gilsum Gorge  
09/18/99    1pm        1470       7.5   Hope
09/18/99    7pm        1190       6.8   willy - pucker
04/02/02    1pm        1120       6.8   willy
04/14/04    noon       1055       6.0   willy  comfortable in Responce
04/16/03    noon        870       6.0   willy - little big for rpm (swim!)
09/19/99   12pm         815       6.0   tom
04/03/02    4pm         780       5.7   willy - nice, even with swim!
04/19/03    2pm         480       5.0   willy - nice in rpm
04/06/02    2pm         440       4.75  Hope  - still fun
04/07/02    2pm         330       4.3 
03/28/02    1pm         321       4.0   Pat   - too low
03/08/02   11am         180       3.8   Pat   - too low
   older suspect Ash data below:
03/12/00    2pm         475       5.5   willy - pleasant
03/13/00    3pm         350       5.0   willy
10/06/99    3pm         247       4.5   Willy - very low
09/26/99   12pm         120       4.2   Willy - too low
          
                               Otter brook bridge (Sullivan)
04/14/04    8am         765       2.75  willy  pushy, even in Responce
03/31/03    2pm         650       2.5   willy - too big for me in rpm, we swim
09/18/99    7pm         415       2.0   willy - nice
04/02/02    1pm         410       2.0   willy -  " , watch one bigger drop 
04/17/03    4pm         370       2.0   willy - just drove by
04/03/02    4pm         280       1.6~  willy
09/19/99   12pm         280       1.5   tom
03/12/00    2pm         240       1.25  willy - didn't attempt
03/13/00    3pm         170       1.0   willy - too low
03/28/02    1pm         144       0.75  willy -  "   "

Tables say time EST/EDT. I interpollated inflow CFS above to time of observation. It bounces around a bit, don't put too much faith in an individual reading! If you get out there, send me or the mvp-list the date, time, and observed gage level and I will add it to this list.

My personal experience is the two rivers above begin to get too low at 5.0 for Upper Ash and 1.5 for Upper Otter. An remember I LIKE rock picking, your min may be higher.

The rivers and gages below probably can be (or have been) correlated. The AWWA pages for NH uses the Ellis as a virtual gage for the Upper Saco. Its apparently a better predictor than the N. Conway gage I've used. My personal records are below with shortcuts to the gages. I find that using the URL directly per below sometimes works when you can't get to the NH-VT river site! My comments on river levels should be combined with the knowledge than I'm a class 3 boater, where I think its pleasant a better boater will think its too low. Where I begin to get some pucker factor, a better boater will just be starting to have some fun.

Souhegan @Merrimack

According to George May, when the internet gage on the Souhegan at Merrimack reports 2280 cfs you can expect the hand painted gage on the Rt 31 bridge (class II put in) to read 2. I think its runable down to something like 1000 cfs (?) which is around 1.5 at the Rt 31 bridge.

Date          Inet gage     observed  gage
              CFS  Stage    Rt 31    Power 
                            bridge   house
03/03/00     ~ 950   -      1.5        -          Wyman
03/18/00      1220  5.1     1.6       1.2         Willy - Pleasant
03/01/00      1200   -       -      ~ 1.7         Moodus
03/17/00      1400  5.4               1.95        Moodus
   -          2280   -      2.0        -          George

Warner @Davisville

The guide lines I've heard are that if the Contoocook @ Henniker is over 9.5' and or the field at 103 and 114 is flooded the top of the Warner is runable. There is now a hand painted gage (thanks Skip) on the Lang Bridge. My home is about 6 miles from there so I will try to watch it and report when I'm in the area. The downstream gage seems to be a consistent.

Date          Inet gage    observed bridge gage
              CFS  Stage
04/17/99       -    4.7        1.3     Even Willy could do it!
03/29/02      410   5.2        1.75    Will  - Contoocook at 7.5'
04/22/03      410   5.45       2.2     Will
04/21/03      550   5.6        2.5     Skip
03/15/00      580   5.6        2.25    Will  - Contoocook at 8.5'
03/22/00      600   5.65       2.4     Will
04/06/02      650   5.75       2.5     Will  - Contoocook at 8.0'
03/19/00      700   5.9        2.5+    David - Contoocook at 9.1'
04/15/03      930   6.3        3.25    Will
03/17/00     1040   6.5        3.0     Will  - Contoocook at 9.2'
03/29/00     1600   7.2        4.0     Will  - Contoocook at 9.6'

Winnipesaukee @ Tilton

There used to be a hand painted gage on the Cross St. bridge, its so faded one can hardly read it so I guess I'll just go with the internet readings here. I have one 5/97 reading of 4.0' for Tilton stage and 2.0 on Cross st. (and I liked it).
Date          Inet gage    
              CFS  Stage
12/97          -    2.5         Tim's cor tbl - min boatable level
10/97          -    3.2         Tim's cor tbl - low
05/97          -    4.0         Will
04/10/99     1000   4.25        Art - medium 

Smith @Bristol

The original rule of thumb I heard was that when the gage at Bristol was over 5 the Cass Mill bridge section was runable. For myself, it looks like 4.0 at Bristol is enough. A word to those who have never run this, don't laugh at the bridge gage reading of 0.0, I find that quite exciting! Also note they rebuilt the bridge. New footings were poured and there is a newly painted gage. Looks similar to old one, but I think its new as of late 1999 (anyone know?).
Date          Inet gage    observed         Comment
              CFS  Stage   bridge gage
fall/99       350   3.8       -    David - little scratchy  but..
4/96           -    4.1      0.0   Tim's cor tbl - very low
4/96           -    4.3      0.4   Tim's cor tbl - low
4/05/02       470   4.2       -    Will - I like this "low" level
3/27/00       560   4.5      0.25  Will - fun, but pushing my limits
4/15/03       550   4.5      0.7   Will & rpm are comfortable but working hard
4/02/02       700   4.8      1.0   Will - really pushing my limits
3/21/00       950   5.4      0.90  Will - just looked, seemed doable
3/29/00      1250   6.0       -    Will - water in trees along 104

E. Branch Pemi @Linclon

I'm used to the gage on the Kancamagus bridge, eventually I'll learn to think in CFS. The serious MVP boaters like it above 2', personally I don't get on over 1.5'. If you like rock picking, and I do, you can run it down to around 3/4'! If you look close you'll see some inconsistency, its likely the gage at Lincoln isn't repeatable over the time span shown. Probably it was recalibrated it between 97 and 99 as the stage seemed to dropped 0.5' for the same reading at the bridge. In 2000 there was a new wrinkle, there was major Kancamagus highway bridge work going on. There was a lot of metal work in the river to protect abuttments possibly changing flow where gage is painted. On 3/31/00 Inet Stage of 2.4' was 0.3-0.4 at bridge
And since 2003 the Stage levels seem about 5' higher than prior years. The CFS readings have been much more consistent. I've run it down to 400 cfs and normally don't get on above 1000. Ran it 4/17 and 18 in 2004. On the 17th it was at 1100 cfs, but only 0.9 on the bridge gage which doesn't agree with the correlation below at all! On the 18th it dropped to 530cfs and 0.75' on the bridge which is in line with data below. No idea what this means....
Date           Inet gage     observed bridge gage
               CFS  Stage
06/97           -    2.6      0.6    will still boatable & fun!
05/21/99        430  2.0      0.8    will nice for me
04/09/99        575  2.3    ~ 0.6    will just looked at it
04/17/03        550  7.0      0.9    will, took out at Loon, nice
04/21/03        600  7.1      1.0    Willy likes it, full run, beautiful day.
05/97           -    3.5    ~ 1.3    will some pucker
05/11/99 PM     -    2.8      1.4    will
  "     noon   1100  3.0      1.5    will
  "      AM     -    3.2      1.8    will to big for me
04/94          2100  3.7      1.8    tim's cor tbl
04/94           -    4.3      2.3    tim's cor tbl

Saco River Shed @N. Conway

I suspect this is just a general indicator as the flow is generated by the Swift, the Ellis, and the Upper Saco. They don't always run together but I thought I'd try to watch it some.

                                  observed gage
Date          Inet gage    Swift    Bartlett 
              CFS  Stage   Gorge    Bridge
04/10/99      3300  5.7    1.4      1.0