Maintenance of drains & vegetation removal from streams Need - - PowerPoint PPT Presentation

Maintenance of drains & vegetation removal from streams

Need for the rules

• Weeds clog up the streams and can potentially cause flooding.
• Spraying of weeds doesn’t work as it can result in the weeds coming

loose and causing problems downstream (such as blocking culverts,

• r damming a stream).
• There are occasions when people incorrectly (and at times

purposefully) use the operative ‘vegetation removal’ rules to remove sediment from the stream bed.

• An attempt to bring best practice into play to reduce the potential

damage to existing habitats.

• Further clarity on the difference between drains, highly modified

waterways, and streams.

Issuesfrom the public

• Uncertainty from farmers about if they have a drain or a stream –

they worry about prosecution

• Often farmers refer to a waterway through a farm as a “drain” when in

reality it’s more than likely to be a highly modified waterway or

• stream. This can lead to them looking at the wrong rules in the plan.
• Farmers are concerned that partial clearing doesn’t work, and their

land will still flood, or that the rest of the vegetation will come loose at some stage and block culverts

• Worry about prosecution if any fish are found dead.
• Confusion over the wooded vegetation rule when it comes to forestry

activities.

Internal considerations

• GWRC groups discussing practicality of

these rules (spanning many departments).

• GWRC had a field day to look at the

practicality of the proposed rules vs existing

• perations.
• GWRC spent a lot of time working on

definitions and rules that would allow these works as a permitted activity, with minimal effects on the environment.

Rule 121

• Rule 39 of the RFP provides for

the removal of vegetation and any associated sediment from any drain, for the purpose of maintaining the original grade or cross section of the channel, as a permitted activity.

• For the purpose of this rule, “drain”

means a highly modified watercourse or river that is channelled to such an extent that it has the characteristics of a farm drainage canal.

• Rule R121 of the PNRP allows, as a

permitted activity, for the maintenance

• f drains, provided the conditions are

met.

• The conditions for rule R121 includes

the excavation of the drain to its original cross section, and the mechanical clearance of vegetation.

• The rule has limitations on the works

such as time of year, amount of drain that can be cleared at one time, provisions for rescuing fish, location of spoil, the removal of wooded debris and use of weed buckets.

Rule 122

• Rule 40 of the RFP provides for the

trimming and removal of vegetation from the bed of any river or lake to avoid or mitigate flooding or erosion, or for the purpose of protecting structures.

• The conditions for this rule states no

contaminants shall be released from the equipment, the release of sediment shall be minimized, restrictions on time

• f year (trout spawning), restrictions on

the disturbance of banded dotterels, public access shouldn’t be restricted, and that all materials shall be removed

• vernight and upon completion of the
• peration.
• Rule R122 of the PRNP provides for the

removal of vegetation (including weeds) from the bed of any river or lake, as a permitted activity.

• This rule is more restrictive around

timing of year works can be undertaken, the use of a weed bucket, provisions for fish to be rescued at certain times, restrictions on the length of wooded vegetation along the riverbed, and restrictions on the amount of streambed that can be cleared at any time. This rule also does not provide for the excavation of the stream bed.

Example – Wharemauku Stream

• Resource consent was applied to

undertake maintenance works in the bed of tributaries of the Wharemauku Stream for:

– The removal of accumulated sediment; and – Removal of vegetation

Wharemauku Stream –

• perative plan rules
• The works will involve the removal of bed material,

and the “drain” was considered a stream under the RMA and therefore they were unable to meet rule 39 or 40 of the RFP.

• Under the RFP the vegetation removal will be able

to meet the permitted activity standards of rule 40.

• It therefore defaults to a discretionary activity under

rule 49 for the removal of bed material.

Wharemauku Stream - PNRP

• As the works were to be undertaken in waterbodies

considered to be a “river”, and involves the removal of bed material, they were unable to meet the permitted activity standards for rule R122.

• As they would be unable to meet the criteria for the minimum
• f 30% of the width left un-cleared (of vegetation), they were

unable to meet the permitted activity standards of rule R122 for vegetation clearance.

• It therefore defaults to a discretionary activity under rule R129

for vegetation clearance and bed disturbance.

General considerations

• It is possible to undertake the works as a permitted

activity, however these changes will likely result in additional consents being applied for.

• It is encouraging best practice, and will result in less

damage, disturbance and deposition in waterways.

• It provides more clarity and certainty around the

definitions.

• If a landowner is unsure if it’s a drain, highly

modified watercourse, or stream, they can just use rule R122 as its more restrictive.