South coast rivercare: Upper Kent River foreshores

Survey and management recommendations
for foreshores of the Upper Kent River

April 1991

Background

The Upper Kent Catchment stretches from near Tenterden to where the Kent River flows into Crown Land south of the Muir Highway. The Kent River is about 100 kilometres long and its catchment covers an area of about 183,000 hectares.

There is a growing awareness within the rural community of the need for the rivers and other watercourses to be fenced and their riparian zones repaired. This would protect these large natural bio-filters and reduce erosion of the riverbanks, which occurs when the protecting fringing vegetation is lost through livestock grazing and trampling.

In 1995, the Department of Agriculture published a Land Management Study for the Kent River catchment. This emphasised the problems facing the upper river catchment and the need for riparian zone protection and management. To assist in the process of riparian repair, the Kent LCDC and the Water and Rivers Commission commissioned Greenskills in 1998 to carry out foreshore work as part of a fencing and catchment rehabilitation repair program.

Foreshore survey

This work graded the condition of the sections of foreshore of each river bank into four categories: (A) pristine to slightly disturbed, (B) degraded, (C) erosion prone, and (D) eroding ditch or weed infested drain; on the basis of weed infestation, soil exposure and erosion. The extent of riverbank fencing and revegetation, and the general qualilty of the fringing vegetation was also assessed. The findings and results of the survey are desgined to promote measures which protect and restore river and stream foreshore condition.

Aims of the foreshore survey

Survey the condition of the Upper Kent River foreshores and its fringing vegetation
Map the extent of fencing and revegetation requirements of the river
Provide a general description of the fringing vegetation and landscape
Provide recommendations for rehabilitation work along the foreshores of the River for future riparian work
Provide a 'snapshot' of the river foreshore conditions at the time of the survey

Results of the foreshore survey

The survey was conducted on both banks of the 63 kilometre section of the Upper Kent Catchment, from near the Albany Highway at Tenterden to where it flows out of farmland south of the Muir Highway. In total 126 kilometres of river foreshores were surveyed and graded. The overall results were as follows:

Amount	Condition
10.5 kilometres (8%)	A grade
42 kilometres (33%)	B grade
67 kilometres ( 53%)	C grade
7 kilometres ( 6%)	D grade

For the 126 kilometres of river foreshores surveyed, there was 99 kilometres (67%) of foreshore fencing in place at the time of the survey. A further 48 kilometres of fencing is required to complete foreshore protection. Overall 83 hectares of the immediate foreshore area requires revegetation to stabilise the banks, and maintain both aquatic and terrestrial corridors.

A survey was also conducted on a priority tributary of the Kent River. This tributary was found to be significantly degraded with 84% of its foreshore in C grade condition, and 17% D grade. It requires a further 9.8 kilometres of foreshore fencing and at least 22 hectares of revegetation in the riparian area.

The river foreshores have many points of salinisation and erosion with significant sections of degradations. Deposits of coarse sediments were observed in the rive bed. Not withstanding the above, significant sections of the river were found to contain foreshores still providing a valuable buffering role, although the effects of increasing salinisation were seen throughout.

Summary

The survey found that some landholders along the river have already expended considerable effort and resources in fencing and revegetation work. Other farmers plan to carry out fencing and related works in the near future, particularly if financial and technical resources were made readily available through government sponsored programs.