This paper is called 'Archaeology of the Wellington Conservancy: Kapiti-Horowhenua' by Bruce McFadgen.
Chapter 4 starts:
The dune belt is widely known for its island pa in Lakes Horowhenua,
Papaitonga, and Waitawa (Adkin 1948; Buller 1893; Rolston 1944, 1947, 1948).
In former times, eel weirs, and eel channels (Whakamate) joining bodies of
water, were especially numerous and some still survive (Adkin 1948; Sheppard
and Walton 1983). Marine shell middens are surprisingly few considering the
long stretch of sandy coast. There are recorded concentrations at only a few
places: west of Lake Horowhenua, on the south side of the Waikawa River, just
north of the Waitohu Stream (Adkin 1948), just north of Waikanae River (Smart
1962), and in Queen Elizabeth Park. Shell middens at two places on the western
shore of Lake Horowhenua are mainly pipi with some paua (S. Forbes pers.
comm. 1995), but otherwise middens on the shores of Lakes Horowhenua and
Papaitonga are predominantly fresh water mussel. Apart from these remains,
sites in the region are either difficult to find, being covered with trees or
pasture, or have not survived the drainage of swamps, farming of the sand
country, or growth of towns.
Figure 6 is a map showing the distribution of Pa, Kainga and Shell Middens recorded by Adkin.
From: http://www.doc.govt.nz/upload/documents/science-and-technical/kapitiarch1.pdf