Regional council river works slammed

Steve Blakemore, former planning and resources manager for GWRC, says the Ruamahanga riverbed has lowered by up to 2m in places after long-term gravel extraction works by the council. PHOTO/FILE

Dried up bores, wells, and natural streams in Homebush are the aftermath of ongoing riverbed degradation, say concerned residents who have blamed the regional council.

Former planning and resources manager for Greater Wellington Regional Council Steve Blakemore has seen a lowering of the Ruamahanga riverbed by up to 2m in places as a result of gravel extraction works in Homebush over the 22 years he has lived there.

Mr Blakemore, who was the planning and resource manager from 1998 until 2005, said GWRC stopped gravel extraction last year following complaints from residents about dried up water sources.

"They've completely dried up a DoC stream that ran through here -- the Pokohiwi stream, and one person's well dried up that had been operating for 100 years," he said.

"Although this stuff is complex, it's all very simple. You take the gravel out, the riverbed drops and the water tables don't get the water in them that they used to get."

Mr Blakemore said, in 2011 and 2012, 44,100 cubic metres was permitted to be taken off beaches along the Ruamahanga River to construct the new Masterton District Council wastewater ponds. A recent report said the council had monitored a "steady bed degrade" over the past 20 years, averaging 2cm a year. The report said residents of the Homebush area contacted the Flood Protection Department and spoke to a GWRC subcommittee with concerns gravel extraction was the cause of river bed degrade and an associated ground water level decline which led to many local residential water supply bores becoming dry.

GWRC have since conducted a "relatively large-scale alignment task" in the affected area, which involved "pushing beaches off with bulldozers" to raise the riverbed level, according to Te Kauru Upper Ruamahanga River Floodplain Management subcommittee project manager Alistair Allan.

"Gravel extraction is likely one of many contributing factors of river bed lowering in this area; however, it is unclear as to how much gravel extraction is the cause."

Mr Blakemore said this effort by regional council to raise the water bed has been "okay" -- "and, if they keep doing it, that's okay because it will slowly lift the bed up".

"But it's going to be a long haul. We may never get to the position to which the stream is a natural stream anymore.

"The degrade has been ongoing and was accelerated by the regional council. You can talk about averages or what not but, at the end of the day, some parts of the river were down by 2m.

"The community is pretty upset here."

Mr Blakemore said he made an official information request last year asking GWRC whether consideration was given to the possible effects on the pool and riffle system of the river and on the aquifer and people's demand for water, but he received no response.

"If a contractor or farmer had dried up streams and damaged river habitat in this way, GWRC would have prosecuted them under the Resource Management Act. However, because two local authorities are involved, it seems to be okay."