Wairoa Stream: Battling the weeds and the weather

We have seen wetter 24 hour periods than than those recorded on 20-21 March 2022. However, what the Metservice historical data does not display, is the condensed time frame that the 115mm of rain (recorded at Kerikeri airport) fell overnight and early morning.

For those who regularly walk or volunteer along the Wairoa Stream track, there was little doubt that this had been the highest level that we had seen during the lifespan of the projects along the stream. Several sections of the track had been well submerged and in some areas the efforts to improve the track surface had been washed away, along with many of our predator traps. The viewing area at the bottom of Te Wairere waterfall had disappeared below a mountain of flood debris and we were lucky that the seat had not been washed away.

The effort required to restore the damage is an unwelcome addition to what is already a busy annual work schedule for the volunteer team that makes up the Friends of Wairoa Stream (FOWS).

We tend to publicise the bigger efforts along the stream such as; track extensions, bridge builds and annual public planting days. While the contribution of the wider community to these larger efforts is critical getting the projects completed, there is a much longer period of ensuring that, especially the native tree plantings, survive. The weed growth in Kerikeri is relentless and controlling the myriad of these (mostly escaped garden species) that flourish in our great growing climate, swallows up most of the man hours of the FOWS who meet every second Monday, often to deal to the weeds by; extraction by hand, strimming, spraying and hacking their way through the unwanted verdant growth and stopping them from overwhelming our younger plantings. This effort can go on for over five years until a canopy is formed and natural weed suppression takes over.

During dry spells we get some respite from the weed growth but then our efforts have to turn to delivering sufficient quantities of water to the newer plantings to ensure that they survive the frequent dry spells that we can experience through spring and summer.

A picture is worth a thousand words so here is a gallery showing some of the recent efforts.

Unplanned Track Maintenance

Howard Smith gets his chainsaw ready to attack some of the larger logs blocking access to the waterfall - a mountain of debris was dumped in this area during the overnight deluge on 20-21 March.

The stream had swept across the viewing area at the edge of the pool at the bottom of the waterfall - almost sweeping the seat away. Lyndesay Turnor fires up his chainsaw.

Back to normal - hopefully for a while.

Weeds and Weed Control

Strimmers and a mower 'release' these Kerikeri High School plantings which were in danger of being overwhelmed.

There are native plants under this canopy of Morning Glory - a job that needs to be tackled soon if we are to save these 4-5 year old plantings on Sammaree Reserve.

Rob Moir deals with yet another recent outbreak of Tobacco Weed - this one on a challenging section beside Te Wairere waterfall.

In Spring the FOWS team spread mulch around the 2021 plantings between Mill Lane and Hall Road - the pictures below show how the young plants have responded to the moisture retention qualities of the mulch - plus a bit of hand watering during the several dry spells this summer.

The plantings alongside the Te Tahawai track (below Placemakers) have responded well to a combination of mulch, watering and weeding. The bare land on the right bank of the stream has been cleared by Avida and will be planted during winter 2022.