When the Public Health Act was introduced in 1872, it caused controversy over sewerage systems as the Act required:
"… all houses within the limits of cities or towns having a population exceeding two thousand souls, whether built before or after such date, shall have attached to them sufficient earth-closets or water closets, and, if the later, with proper drains communicating with a main drain; and if in any of the said towns or cities a system of drainage and water supply shall not for the time being exist, the Local Board shall make adequate provision for supplying the occupiers of houses with earth for use in earth-closets, and removing the same from such earth-closets."
However, John Plimmer - regarded as one of Wellington's 'founding fathers' - was strongly opposed to the development of an extensive sewerage scheme. He suggested that surface drainage and nightsoil could "pass into the harbour without any detriment to the bay". Plimmer was supported by a number of businessmen who argued that the high cost of the scheme would result in substantial rates increases.
In 1875, the Official Handbook of New Zealand stated that "Wellington only needs proper sanitary arrangements to be one of the healthiest cities in the world". By the 1880s, the city was often referred to as the worst drained city in the colony." The newly elected holder of the civic chair, Mr HD Bell, was determined to improve Wellington's reputation.
In March 1890 Wellington City Council appointed a drainage commission to report on the state of sewerage in the city. The commission consisted of two engineers - Mr E Cuthbert of the Christchurch Drainage Board, and Mr W Ferguson of the Wellington Harbour Board.
In July 1890 the commission recommended a scheme that provided for construction of:
- a sewerage network in the areas around the harbour
- a sea outfall at Moa Point
- a sewerage tunnel through Mount Victoria
- overflows created by transforming some existing timber stormwater culverts into brick or concrete.
The scheme was adopted and after considerable delay work commenced in June 1893. Works were completed in 1899 at a total cost of £175,000.
In his final report, the Resident Engineer highlighted the substantial decrease in sewage-related diseases being treated at Wellington Hospital since the introduction of the new sewerage scheme.
Since then requirements and attitudes to sewage collection and treatment have evolved and developed to a high standard.
In 2004, Wellington City Council collaborated with Hutt City Council to establish Wellington Water (formerly called Capacity), a non-profit organisation that now maintains the sewerage, water and stormwater infrastructure for both councils.