Re: [RML] Rocky Bottom Creek

Adrian R. Tappin (atappin at
Wed, 17 Sep 1997 06:08:59 +1000

At 10:08 16/09/97 +1000, Barry wrote:

>Just to add my two cents worth on the Rocky Bottom Ck tri. I was on the
>expedition that bought these back to Brissy. Geographically Rocky Bottom Ck
>does not flow into the Goyder River - it flows into the Arafura Swamp. The
>Goyder also flows into the Arafura swamp. As far as I know there has been
>no surveys done in the Arafura Swamp at this stage. We intended to survey
>from the old Arafura HS on this particular trip but couldn't convince the
>land councils to allow us north of the Bullman Road. As an aside the swamp
>has a nasty reputation with respect to swamp-dogs (as does the Goyder R).

Further information for those interested:

The Arafura Swamp occupies the broad floodplain (Muckaninnie Plains) of the
Goyder and Gulbuwangay Rivers, which form the Glyde River near the
downstream limit (narrowest part of the plain: 1.5 km wide).
A major flood control and sedimentation basin on the Goyder-Glyde river system.

Water supply: Surface inflow, mainly from Goyder River, originating 125 km
south, and Gulbuwangay River, originating 45 km east and south-east, and
numerous creeks off the surrounding scarp, mostly a few km long but up to 33
km in south. Total catchment (950,000 ha) and is relatively undisturbed.

Inundation: Seasonal, apart from active and old channels that may be
permanent; tidal influence (Glyde River) extends 5 km into the swamp.
Greater part of the Swamp has no free standing water in very dry years.
Water depth: Average annual increase in depth is 1.94 m (range: 0.4-3.5 m);
refilling starting in January, water deepest in April, depth static by
October. Water salinity: Fresh, probably stasohaline.

There has been no systematic survey over the whole site. The Threadfin
Rainbowfish Iriatherina werneri, has been recorded in the Swamp. Its a major
breeding area for both fresh and salt crocodile species. Saltwater
crocodiles occur in high densities, especially in billabongs near the
northern end, e.g. up to 30 crocodiles per km of billabong length.

Most of the swamp was burnt in June-December 1990, the driest year in 40.
The site has a pastoral history of 100 years, but few feral cattle and
buffalo now occur and some cattle are run in fenced areas at the north and
west edges. The site is not yet badly affected by the exotic shrub Mimosa
pigra (a few plants found in 1992 and subsequently) and there are few other
weeds, there are no saltwater intrusion effects, and damage from pigs and
cattle/buffalo is minor (pigs have recently reached the area). The Cane toad
Bufo marinus is expected to reach the area within five to ten years.

Current land ownership : Aboriginal freehold (Arnhem Land Aboriginal Land

Adrian R. Tappin
"Home of the Rainbowfish"