River Road - Civil Design Report

Beca //04 August 2016

3124460 // NZ1-12891696-39 0.39 // page 1

1 Introduction

Ryman is seeking resource consent to construct and operate a retirement village at River Road, Hamilton.

This document sets out the proposed civil engineering works, assessment of effects and associated

mitigation measures for the construction and operation of the village. Preliminary design drawings have been

prepared for earthworks, stormwater, water supply, wastewater and utilities for the full site. This report sets

out the design basis behind those drawings and describes assessments that were carried out to:

� Demonstrate how stormwater quality and quantity is to be managed including consideration of potential

flood risk effects both within and downstream of the site.

� Demonstrate that the site can be serviced taking into consideration the capacity of the local network and

requirements of local authorities and utility companies.

� Demonstrate how erosion and sediment control requirements can be met for the expected earthworks

concept.

River Road - Civil Design Report

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2 Site description

The site is located as shown on Figure 1 and is bounded by residential properties to the east and north west,

by Featherstone Park to the south-west, by River Road to the north and the Waikato River to the south. The

site is currently accessed from River Road.

Figure 1 – Site Location

The site is 8.36 hectares, with a maximum length of 410 metres north to south and 253m west to east. The

site is defined by two titles being Lot 3 DPS 8875 (western site 4.67ha) and Lot 2 DPS 8875 (eastern

allotment 3.69ha).The site is zoned Residential under the Hamilton District Plan and General Residential

under the Proposed Hamilton District Plan.

Most of the site is in grass with intermittent trees other than the river slopes along the southern boundary

which are covered in thick vegetation. Three small utility sheds are located on the site; two along the

northern boundary and one near the centre of the site.

Descriptions of the site geology and an assessment of geotechnical constraints are provided in a separate

report, Tonkin and Taylor, July 2016: “Geotechnical Investigation Report North of 1761 River Road,

Hamilton”.

River Road - Civil Design Report

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The site comprises three gently sloping river terraces with steeper slopes (generally 8H:1V to 4H:1V or 7° to

14°) between each terrace and along the channel which crosses the north western corner of the site. The

maximum elevation is at the north western corner (RL 36m) with the lowest elevation at the southern

boundary near the bank of the Waikato River (RL 12m). The elevation difference between the terraces is

typically 4m to 5m and the elevation difference between the lower terrace and the banks of the Waikato River

is approximately 12m.

Based on our site inspection, a review of Hamilton City Council (HCC) GIS information and a review of the

Waikato Regional Council (WRC) Flood Hazard Mapping it was found that the site has a low risk of flooding.

The most significant existing overland flow paths through the site occur via two watercourses which traverse

the site. The upper watercourse runs from River Road south-west and discharges into Featherstone Park.

Its uppermost reach is dammed. The lower watercourse cuts through the very south-eastern corner of the

site. A description of the stream ecology on the site is provided in a separate report, Freshwater Solutions,

August 2016: “1765-1785 River Road Stream Ecology Assessment”.

Figure 2 below shows the site topography and existing landcover. A topographical survey is included within

the architect’s set of drawings (Drawings 6134-00-SU-050 and 61364-00-SU-051).

Figure 3 shows photos of the site. It is noted that these were taken on a day of very heavy rainfall in

Hamilton.

River Road - Civil Design Report

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Figure 2 – Site landcover, and existing topography

Photo 2

Photo 1 (with dammed upper reach) Photo 2

Photo 3 Photo 4

Photo 5 Photo 6

Figure 3 – Site photos

River Road - Civil Design Report

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3 Proposed retirement village

The proposed retirement village will include a mixture of townhouses, apartment blocks, assisted living units

and care beds. The total potential impervious area will be just over 4 hectares, 2.7 hectares of which are the

buildings. The overall impervious coverage is approximately 54% of the total site area.

The Ryman drawings included in Appendix A give a more detailed breakdown including the site coverage,

number of carparks and residences.

Figure 4 – Proposed retirement village – Source: Ryman