THE PROPOSED ALIEN REED MAINTENANCE WITHIN THE ONRUS RIVER ESTUARY
Posted on the 9th November 2019
NOTIFICATION OF PUBLIC PARTICIPATION PERIOD: 31 October 2019 – 6 December 2019
GNEC Code: 50348
Dear Interested and Affected Party
NOTIFICATION OF START OF THE PUBLIC PARTICIPATION PERIOD FOR THE PROPOSED ALIEN REED MAINTENANCE WITHIN THE ONRUS RIVER ESTUARY, ONRUS RIVER, WESTERN CAPE.
The Onrus River Estuary Forum otherwise known as OREF proposes the alien reed removal and maintenance within the Onrus River Estuary. The removal and maintenance are proposed from the mouth of the Onrus River Estuary up to the R43 bridge approximately 2km upstream of the mouth. The Onrus River Estuary is in the Overstrand Local Municipality area in the Western Cape Province and is included in the Breede-Gouritz Catchment Management Area (BGCMA). The Onrus River rises in the Babilonstoring Mountains and flows approximately 16 km through the Hemel en Aarde Valley before crossing the narrow coastal plain to discharge into the sea via the Onrus River Estuary, which is situated approximately 7 km northwest of Hermanus.
Due to the change in catchment land uses (agricultural activities, vegetation removal, urbanisation, instream impoundments) over the past few decades, the increase of sediment deposition changed the Onrus River Estuary from a seasonally closed Estuary with a relatively large open water lagoon to a shallow lagoon dominated by robust reed species. Building of the instream De Bos dam (approximately 7.2 km north of the mouth) resulted in the reduction of flood events that could flush sediment from the river mouth. Consequently, robust reed species, specifically Phragmites australis, established in these deposited sediments which are no longer flushed out either by tidal action or by river flow.
The monoculture of reed species reduced the overall biodiversity of the Estuary and discourages the use of the Estuary for recreational purposes. As such, it is required that the reed species be removed in order to improve the ecological integrity of the Estuary.
It is therefore proposed that the monoculture of reeds in the Onrus River Estuary be removed and maintained. Management options that are available include cutting of reeds by means of a mechanical reed cutter, with potential follow up treatment using the application of herbicide, and dredging, which entails the removal of sediment and reeds through the use of a dredge.The recommended reed control measures are described in detail in the Maintenance Management Plan and Ecological Assessment. As both these methods entails the stockpiling of reeds after removal, these reeds may not be burned on site due to the surrounding urbanised areas and the seeds may disperse and/or the plants may re-establish in these areas. Cut reeds may be stockpiled in a designated area to allow the reeds to dry out and be compacted for eventual transport, outside the delineated boundary of the watercourse, where after it will be removed to a registered disposal facility.
Guillaume Nel Environmental Consultants (GNEC) was appointed by the Onrus River Estuary Forum (OREF) to facilitate the requirements of a Maintenance Management Plan for the proposed removal and maintenance of the alien reeds within the Onrus River Estuary.
Taking the above-mentioned proposed maintenance activities into account, the following listed activity will be triggered:
Government Notice No. R.983 of 2014 (as amended 07 April 2017):
The infilling or depositing of any material of more than 5 cubic metres into, or the dredging, excavation, removal or moving of soil, sand, shells, shell grit, pebbles or rock of more than 5 cubic metres from –
(i) the seashore;
(ii) the littoral active zone, an estuary or a distance of 100 metres inland of the highwater mark of the sea or an estuary, whichever distance is the greater; or
(iii) (iii) the sea; - but excluding where such infilling, depositing, dredging, excavation, removal or moving –
(a) will occur behind a development setback;
(b) is for maintenance purposes undertaken in accordance with a maintenance management plan;
(c) falls within the ambit of activity 21 in this Notice, in which case that activity applies; (d) occurs within existing ports or harbours that will not increase the development footprint of the port or harbour; or
(e) where such development is related to the development of a port or harbour, in which case activity 26 in Listing Notice 2 of 2014 applies.
The aim of this RMMP process is to ensure that:
• Public participation will be conducted, i.e. to afford stakeholders and/or the community sufficient opportunity to provide comment on the proposed maintenance activities; and
• Sufficient information is submitted herewith to decision-makers to support an informed decision-making process.
The Public Participation Process will run from the 31st of October 2019 until the 6 th December 2019.
Please refer to GNEC’s website (www.gnec.co.za) to access the RMMP documents or visit the Hermanus Library (66 Duiker Street, Hermanus) for a hard copy of the documents.
Individuals Interested and/or affected by the proposed project are invited to register with Guillaume Nel Environmental Consultants as an Interested and Affected Party (I&AP). I&APs should refer to the GNEC reference number 50348 in all correspondence, and must provide their details including:
Name, contact details, preferred method of correspondence (e.g. e-mail address or fax) and an indication of any direct business, financial, personal or other interest which they have in the application to the contact person indicated below within the timeframes mentioned above.
Should you have any queries, please feel free to contact me at:
Tel: (021) 870 1874
Fax: (021) 870 1873