A reconfiguration of the parking area is planned parallel to an upgrade of the Department of Conservation-owned toilet block septic system.
Doc is seeking resource consent from the West Coast Regional Council to change the location of about 50% of the underground field drainage lines.
Currently, wastewater is pumped to a green area of an existing carpark area.
That area will be sealed and modified to extend parking, kerbing and landscaping at the entrance to the lake area.
The site is managed by Doc as part of Westland Tai Poutini National Park.
Facilities at Lake Matheson were last improved six years ago with a $3.9 million government boost.
In February 2019, a major slip blocked part of the access road to the glacier itself. To offset the closure, a cycling/walking trail was created to link the lake with Cook Flat.
A neglected track leading from the eastern side of the Lake Matheson Walk to a circuit around Lake Gault, an 8km return trip, was also upgraded.
Lake Matheson is the second site where Doc is investing in new infrastructure this year.
Increasing numbers of visitors are also straining the sewerage system at the Lake Ianthe campsite.
Doc applied late last year to add a second septic tank and an additional set of underground pipes.
A report with the application says the system, which uses a sand bed to treat and disperse septic tank effluent, was ‘‘failing’’ due to overloading.
Last summer, the toilets were closed while blocked pipes were emptied.
The size of the existing system had been based on recorded flows from the Otto-McDonalds Campsite at Lake Mapourika, which has an average water use of 1800 litres a day.
However, the Lake Ianthe campground use is estimated to be up to 150% higher than that.
— By Janna Sherman
