Coca Cola Anyone?

Near where I am parked at Tokerau Beach (X on the map)
is Lake Rotopokaka...
More commonly known as 'Coca Cola Lake'.
It is a large lake, set in beautiful surroundings,
with soulish  moods that change with the weather.
On sunny days it looks a shimmering blue
but on a closer look the lake is a reddish brown.
Hence the 'Coca Cola' moniker.
Various explanations have been given for the colour...
It may be due to a dye coming out of the flax roots
that grow prolifically nearby.
Bathing here is popular, the water conditions
skin and hair to a beautiful softness.
It's just a short walk over scrubby sand dunes
from the long sandy swimming, fishing beach where I am.