Most Australian wetlands go through a cycle of wet and dry - and native
wildlife is readily adapted to survive periods of dry. Wetlands with changeable
water levels are ecologically more productive than those that aren't (think the
urban lakes).
In terms of Kellys - the last time it completely dried to the point you could
walk a group of school kids across it was in 2013. Some years it retains a high
level all year. The drying event in 2013 was beneficially in that it killed all
the carp that had got in during the Feb 2002 flood when Kellys became as one
with Lake Burley Griffin.
Kellys is not connected to Jerra Creek or the Molonglo - which protects it from
carp and potential pollution events from Fyshwick industrial area. It is not
connected to the sewerage works, except for some surface rain flow. Water from
sewerage works is piped to the Molonglo treatment works before discharge into
the Molonglo/Murrumbidgee.
Kellys gets its water from rainfall and sub surface flow from adjacent high
land (eg old sand dune ridge where cattle graze). During big rain events the
water level slowly rises over several days due to sub surface flows, where as
the Billabong rises rapidly as it gets a big inflow from the stormwater system
of Fyshwick.
There is an 'outlet' valve at Kellys (north end of boardwalk) so water can be
let out into Jerra Creek - but not in.
Drying of Kellys is good for waders, crakes, rails, snipe as mud is exposed.
In an ideal world there would be 3 or more "Kellys Swamps" and water could be
pumped around so all would go through a differing cycle of wetting and drying
to provide optimal habitat for most species (not just birds but frogs, macro
inverts, turtles etc).
Michael Maconachie
Senior Ranger
Jerrabomberra Wetlands Nature Reserve
ACT Parks and Conservation
0428 113 533
www.jerrabomberrawetlands.org.au
-----Original Message-----
From: Richard Lane
Sent: Saturday, 30 March 2019 1:28 PM
To: Canberra Ornithologists Group <>
Subject: Jerrabomberra Wetlands now living up to its name
As a relative newcomer to the wetlands, I was surprised at how quickly the main
swamp dried up over the past 2 months. It was sad to see it almost completely
dry, and of course, to have the water birds leave for other locations.
On Saturday morning (30 March 2019), I was pleasantly surprised to find the
return of a significant amount of water following just one night of rain. With
the return of the water, there were a good number of waterbirds there, as well
as a flock of a hundred or so seagulls.
As I stood there enjoying the scene, I had a number of questions run through my
head. I have expressed them below, and any answers from those with more
knowledge of the wetlands would be very gratefully received.
How often does the swamp dry up? Is this an annual Summer event?
Is the swamp fed by a combination of groundwater and stormwater? Or just one or
the other?
Is there any control of the water inflow by the folks at the treatment works
across the road?
... Richard Lane
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