The council needs to act now to clean up Sullivan Lake's water quality, says the lake's care group.
A petition with over 300 signatures calling on Whakatāne District Council to clean up the lake and improve its water quality was presented at the council's long-term plan hearings last week.
Sullivan Lake Care Group's Lynore Craig told the council there was a growing problem at the lake and the council needed to act now and put a plan in place to remove the silt accumulating on the bottom.
"Council needs to look after its existing assets and ensure they are of a reasonable quality and standard," Craig said.
"This is a beautiful reserve; the council is looking at extending the walking path, but we need healthy water. We are disappointed an asset like this is not being looked after."
The problem with the water stems from its role as a stormwater basin. It receives and stores stormwater through 10 pipes, including from the industrial area of Te Tahi Street.
With the water comes silt and pollutants, which build up at the bottom of the lake. Craig said the lake in 1992 was 2m deep. In 2015 it was 1.2m deep.
The accumulation of silt was threatening the lake's role as a stormwater reserve and the shallow water warms up faster, leading to the growth of bacteria and the death of birds by botulism, Craig said.
The warm shallow water also led to increased weed growth, which in turn contributed to the unhealthy state of the water.
The weed problem had become so bad, members of the model boat group could no longer sail their boats on the lake. To combat that, the care group wanted the council to dredge a section of the lake every two years.
"Climate change is raising the risk of more severe weather events so the need for a reliable stormwater holding area is critical," Craig said.
"We have had rain events where the reserve has flooded, and the water has come up to people's doorsteps."
The lake group has been active in caring for the reserve including collaborating with other community groups and the Department of Corrections to do planting and pest trapping, but only the council can dredge the lake.
The water quality is also affecting the wildlife in the reserve. Birds die in summer from botulism and some years ago tadpoles and frogs could be seen in the lake, but no more.
Craig said a plan to build 30 more homes on the old supermarket site in Kopeopeo had made the issue more pressing as it was important those living in the homes had access to a green space.
The council will be deliberating on its long-term plan next week. The plan sets the direction for council and outlines projects for the next 10 years.
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