[Jim MooreParticipant]

I have had two Beaver attacks on the Marsh creek sensor stations; BCMC3S at Moores rd and BCMC4S at fairview rd. Beaver tend to bite anything that gets in their way while in the water.  In both cases the Beaver cut the CTD-10 cable which in addition to the signal wires provides the atmospheric reference pressure for the depth reading which uses the differential pressure between the sensor port and atmospheric reference.  This is about 1.5 psi per meter of depth.  These sensors cost $461 each and cut cable can’t be repaired to provide depth readings so if replacement is not in the budget (GMI’s) the signal wires can be spliced and covered with waterproof tape (self annealing rubber tape) to at least restore temperature and conductivity readings.

I have implemented a beaver proof design which has been successful so far at Moores rd where beaver attacked a few years ago.  I ran both cables thru 3/4″ aluminium flex conduit attached to the sensor bundle and run up the pole to the Mayfly box as shown in the attached photos.  I don’t use a pins in the PVC bundle pipe which are a real PIA to unfashion especially in cold water!  Instead a cap with a 1/4″ hole in it to prevent flotation seems to work quite well.  The sensor bundle rests on the steel forming stake and then the bundle can be removed for cleaning just by pulling up the attached flex conduit.

BCMC4S was redeployed 6/13/2020 at 16:50 EDT and the temp and EC appear normal.  The depth readings that are being reported should be ignored as they are not meaningful.  Question for @hicks or @damiano:  Can I delete the CTD depth reading in MonMW without screwing up the other data or does it need a programing tweek?

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[Jim MooreParticipant]

Here’s a link to flex conduit at Lowes

[David BresslerParticipant]

@moore, you are not able to overwrite 0r remove data on MonitorMW, so no you will not be able to remove depth data.  You could do programming adjustments so that depth data don’t report anymore but I’m not sure if that would be worth your while.  You might want to describe in the “Notes” section of the MonitorMW page for that site that the pressure transducer was damaged on ?date and that data are not valid after this date.

@hicks and @damiano may have other suggestions.

[Jim MooreParticipant]

Thanks for the info Dave.  Lori did update the wiki log and put in a note to the effect that CTD depth data at BCMC4S should be ignored.

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