Ākitio Upper Weir Project

The Rabbit Weir, located approximately 48 km up the Ākitio River from its mouth at the coast, formed a part of the Southern Hawkes Bay Rabbit Fence (SHBRF) that was built between the years 1884 and 1890 to halt the northward migration of rabbits from the Wairarapa into the Hawke’s Bay District (Poulton, 2000). The SHBRF ultimately failed this objective and starting about 1925 the rabbit fence was replaced with a conventional seven- or eight-wire fence (Poulton 2000: 28). According to Poulton (2000: 28) the last surviving substantive section of rabbit fence, at Kumeroa, was replaced in 1995. With the rabbit fence now mostly dismantled or destroyed, the Rabbit Weir is the lone substantive remnant, albeit highly modified, of this once extensive structure.

It is somewhat remarkable the SHBRF only crossed two major bodies of water – these being the Ākitio River and the Mangatoro Stream – given the length of rough hill-country that it traversed. The fence line intersected the Mangatoro Stream at a location where the depth of water acted as a natural barrier, with two wings extending from the rabbit fence along both sides of the stream to a steep cliff a short distance above the crossing (Poulton 2000: 3). The Ākitio River was a broader body of water, but one that ran shallow during the summer months and required a different solution. To this end, the Trustees of the Hawke’s Bay Rabbit Board sought the opinion of the City Engineer, J. D. Baird, on how to best dam the Ākitio River in order to maintain a deep-water barrier throughout the year (‘[untitled]’ 1888b). One month later, the City Engineer reported back with an estimate of £200 to construct a timber weir and was then commissioned by the Trustees to prepare full plans and specifications (‘[untitled]’ 1888c). Much of the official information about the SHBRF that would ordinarily be preserved in official archives, and by association the Rabbit Weir, was destroyed in the post-Napier Earthquake fire. What little that is known of the weir can be summarised as follows:

An advertisement in the Waipawa Mail of 10 January 1889 requests tenders to deliver “about 14,500 feet sawn and squared timber, where the Waimata Rabbit Fence crosses the Akiteo [sic] River.” (‘Hawke’s Bay Rabbit District Board of Trustees’ 1889a);

An overseer, quarrymen, ironwork and tools were sent via Cape Turnagain, aboard the Kiwi, and Riddel and Warrin’s “tender for squared 7245 feet of timber for the Akiteo [sic] dam” was accepted (‘H. B. Rabbit Board’ 1889);

The firm of Burt and Ward started work on the Rabbit Weir in late February or early March, 1889 (‘Hawke’s Bay Rabbit District Board of Trustees’ 1889b; ‘[untitled]’ 1889);

The contract/s for the preparation of timber was completed before the 11th of April that year (‘Hawke’s Bay Rabbit Board’ 1889), and construction of a weir 4 ft 6 inches height was completed by early June (‘The Rabbit Fence’ 1889); and,

Poulton (2000: 3) states that the Rabbit Weir was 29 m long and “was built with the fence coming in at each end for a short distance”, presumably from first hand observation or a local informant.

As with the introduction of the rabbit, the construction of the Rabbit Weir on the Ākitio River would also have unintended consequences: though of a much less grave nature. By 1974, 85 years after its construction, the Manawatū Catchment Board had become concerned that the Rabbit Weir had “introduced a permanent 2 foot step into the bed of the Ākitio River” and that “Should this weir give way the consequent fall of the river bed… could undercut the toes of stable banks, accelerating the degree of slumping” that would “prove very expensive if they occur where the river is close to State Highway No. 52.” The County Council agreed to the Catchment Board’s recommendation that the weir should be repaired and maintained for an estimated cost of $2806. In more recent times, there is greater concern about the Rabbit Weir impeding fish species that require movement between freshwater and saltwater environments to complete their lifecycle.

The Catchment Board’s repairs would:

1. Box in the weir face.

2. Fill the inside cavity with concrete.

3. Bolt onto the concrete crest a level 96 foot long steel ‘H’ section rail 8 inches high.

The work would also raise the water level upstream of the weir by at least another foot. The only known images of the Rabbit Weir in its original form, albeit weathered and damaged, were taken by the Catchment Board at this time and document the weir before modification (Figures 1 and 2). At the same time as the Rabbit Weir was being repaired, the Saltwater Weir further down the Ākitio River was also repaired in a similar fashion but with some minor differences to account for local conditions. Figure 3 shows the repair of the Saltwater Weir in progress and is indicative of the repair work that was undertaken on the Rabbit Weir.

Unfortunately, the Rabbit Weir (as well as the Saltwater Weir) is an impediment to the movement of migratory freshwater fish species that require connection between the freshwater and saltwater to complete their lifecycles. Under the [National Policy Statement for Freshwater] NPS-FW, regional councils are required to identify and prioritise the remediation of fish barriers. The implementation of which is guided by Te Mana o te Wai (MfE 2021).

Tonkin & Taylor (Quilter 2020) were commissioned to evaluate the feasibility of two options for remediation: construction of a rock ramp (i.e., fish pass), or deconstruction and removal of the weirs. Horizons agreed that the Tonkin & Taylor (Quilter 2020) recommendation of the removal of the Rabbit Weir is the more beneficial and feasible option.

The removal of the Rabbit Weir adversely affected an archaeological site of special heritage value, with significant historical value in regards to the unforeseen hazards and enduring legacy of environmental intervention. The Rabbit Weir and SHBRF are also of social significance to the local community through the organisation, financing and labour of the families and personalities that contributed to the development, construction and maintenance of these structures. However, the adverse effects are somewhat mitigated by deconstructing the Rabbit Weir and preserving sections for public display at three locations: Dannevirke Museum, Pongaroa, and Weber. While this does not completely mitigate for the loss of the Rabbit Weir in its authentic context, it does provide an opportunity for public recognition and education about the historic and social themes. Given the significance of the SHBRF and the Rabbit Weir to the local community, it is notable that the removal of the Rabbit Weir was supported by the local community and iwi.