Environment Waikato has approved stormwater consents for towns in the Waipa District.
Waipa District Council had applied for comprehensive urban stormwater discharge consents for Cambridge, Leamington, Karapiro, Te Awamutu, Kihikihi, Pirongia, Ohaupo and Temple View. Eleven submissions were received from the Department of Conservation, New Zealand Milk Products, Pirongia Residents and Ratepayers Association and other residents within the District.
The consents authorise the use of discharge structures, and the diversion and discharge of urban stormwater runoff and associated contaminants to receiving waters and land in Waipa’s main townships.
The District Council’s senior engineering officer Steven Cornelius identified stormwater quality effects on Lake Te Ko Utu as the most significant stormwater management issue in Cambridge. Options for mitigating the effects of stormwater and restoring the lake were being investigated. Erosion was also resulting from stormwater flows in Leamington's Cemetery Gully Stream, he said.
Other issues included contaminants entering stormwater systems from commercial and industrial sites, localised ponding at an Ohaupo site, flooding at Temple View, diffuse sewage contamination of stormwater from septic tanks and leachate contamination of stormwater from the Kihikihi closed landfill.
In submissions, the Department of Conservation expressed concerns about the potential for stormwater discharges to adversely affect indigenous flora and fauna through loss of habitat and degraded receiving water quality.
Residents had concerns about the effects of stormwater on Te Awamutu streams, contamination from sewerage system overflows, deterioration of Lake Te Ko Utu and the effects of future stormwater discharges on the Mangaone Stream as a result of urban development in Cambridge.
In making its decision, the Hearing Committee said it recognised the complex nature of urban stormwater and the challenges of its effective management, particularly in view of the diverse range of land use activities that take place in urban areas. The Hearing Committee supported the development of Stormwater Management Plans that identified a range of initiatives to improve urban stormwater management.
It said the Council should be more proactive in taking steps to avoid, remedy or mitigate sources of stormwater contamination, particularly those it already knew about. It was also concerned about stormwater discharges from state highways, which were the responsibility of the roading authority.
The Hearing Committee agreed to include conditions to reflect DoC’s concerns about the potential effects of stormwater on receiving environments, and other submitters’ concerns about contamination from commercial and industrial sites and the management of Lake Te Ko Utu in Cambridge.
The consents were granted for 20 years with an option to review conditions within three months of the 3rd, 6th, 10th and 15th anniversaries of their commencement.