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Sheldrake Lake, Hubley

Soil & Water Conservation Society of Metro Halifax (SWCSMH)

Updated: August 08, 2018      Woodens River watershed



Water Quality

Select scientific modelling and chemical/biological limnology are part of our miscellaneous archives

The bathymetric map; the morphological data; the flow chart of the Woodens River watershed;
peruse our predictive modelling, and view a relevant model; the Nova Scotia lake hypolimnion project; the paleolimnology of lakes in the HRM


We, SWCSMH, had carried out chemical/biological limnology of Sheldrake Lake as well as the Predictive TP modelling of the entire Woodens River watershed during the early 1990s commencing in 1991. As a result, we concluded that hypolimnetic aeration was the simple, economic and practical restoration methodology for Sheldrake Lake. We subsequently wrote a letter to the Hon. Robbie Harrison, Minister of the NS Dept. of Environment in May of 1994 recommending same (only the relevant part of the letter is linked).

Dealings with the Sheldrake Lake Homeowners Association in 1994

On September 12, 1994, we made a detailed presentation using overheads to several members of the Sheldrake Lake Homeowners Association headed by Mr. Michel Desy PEng. Subsequently, Mr. Desy was kind enough to send us a letter dated September 26, 1994 supporting the concept of hypolimnetic aeration at Sheldrake Lake.

On a subsequent telephone conversation I had with him though, they were not interested in spearheading the project, and since I, Shalom M. Mandaville, live in Dartmouth, it was not convenient for me to drive back and forth as a total volunteer. In addition, my priorities have always been in continuing my research in Applied Limnology.

As it is, I spent a horrific amount of time driving back and forth all the way from Dartmouth almost on a monthly (and sometimes on a biweekly) basis during the period, 1991-92, carrying out field sampling as a total volunteer assisted mostly by an extremely dedicated/concerned local resident, Mr. Walter Pilon, and on a couple of occasions, by a resident of the Sheldrake Lake subdivision, Mr. Terry Conrad.

Because of the reasons explained in the preceding paragraph, I abandoned the project until a handful of members of another local group, the Woodens River Watershed Environmental Organisation, (WRWEO), expressed an interest in carrying out the project.

Extensive dealings with the Woodens River Watershed Environmental Organisation (WRWEO)

On May 04, 1999, the Woodens River Watershed Environmental Organisation (WRWEO) invited me (SWCSMH), to make a detailed presentation to them; the meeting was held at the home of Frank Hope at Three Brooks, Hubley Big Lake, Hubley, and they, specifically Frank Hope and Tim McGee, Directors of WRWEO, became quite enthused. This particular meeting took me from approx. 6 PM to 11 PM including travel time from my place in Dartmouth.

Several further discussions took place via meetings and emails during 1999-2001, and on our suggestion, WRWEO obtained the services of a reputed lake aeration specialist, Mr. Kenneth Ashley, of the B.C. Ministry of Fisheries. WRWEO has been instrumental in obtaining a major Federal funding (EcoAction) among other sources, and hopefully all of our efforts will lead to success.

Relevant excerpts from the report by Mr. Kenneth Ashley have been inserted towards the end.

The two relevant emails from WRWEO's aeration consultant, Ken Ashley of British Columbia

Date: Sun, 24 Jun 2001 20:16:56 -0700
From: "Ashley, Ken FISH:EX"
To: "''" <>
Subject: Sheldrake lake oxygen and temperature data

>Hello, I would like to get access to vertical oxygen and temperature profile data for Sheldrake Lake so I can provide Tim McGee and Frank Hope with advice in designing a hypolimnetic aeration system for Sheldrake Lake.

Your assistance would be greatly appreciated.
Ken Ashley

Mr. Ashley sent the below follow-up email on June 26, 2001:

Date: On Tue, 26 Jun 2001, Ashley, Ken FISH:EX wrote:
From: "Ashley, Ken FISH:EX"
To: "'S.M. Mandaville'" <>
Cc: 'Frank Hope' ,
'Tim McGee'
Subject: RE: Sheldrake Lake oxygen and temperature data + IMPORTANT CAUTION NS

Mandaville, thank-you very much for your detailed comments re: the background on Sheldrake lake. All I need is the field data from 1991-92 for oxygen and temperature. Regarding the oxygen-temperature data, I once again tried to download the data from the web site that you indicated http://www.chebucto.ns.ca/Science/SWCS/DATA/data-s.xls, and I am unable to do so (semi-web illiterate I guess).

Is it possible to simply forward me the Excel files of the oxygen-temp data for the few years that Sheldrake was sampled on at least a monthly basis in the summer and winter so I can make some estimate of the hypolimnetic oxygen demand. It would be greatly appreciated.

I would like to compete my report for Woodens River as quickly as possible so that they get the correct picture on what hypolimnetic aeration can and cannot do, and do not waste any of their money on "pie in the sky" ideas. I agree with your comments, and my report will reflect that, including the issue of non-point source nutrient loading and sustainability.

Ken Ashley

The design report of Ken Ashley

Caution: There have been some failures of lake aeration per relevant papers published worldwide. In most cases, the failures were due to insufficient sizing, improper installation, poor maintenance, or for other reasons. In some cases, aeration led to worse water quality but the reports only speculated on what the reasons could be. One should not be discouraged by failures. Persistence does reward eventually. There are also several commercial aerators available which may perform better than those assembled by volunteer groups. Commercial aerators are costly but do have a warranty.



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