Category Archives: Demographics

Development Contributions (DC) higher density traffic bonus

Posted on by 1 comment

Looking at the statement in the Outline of significant changes to the Development Contribution Policy 2018/19 – Page 5

“Under the existing policy some high-density developments received a discount for placing lesser demand on the Council’s services – but in fact placed demand equivalent to those of larger dwellings”

Note the key word change here is “high-density” in the proposed DC policy reports, whereas it was “higher density” in previous DC policy. When it comes to traffic in Hamilton, increasing (higher) density cannot be said to place equivalent demands on roading infrastructure as lower density areas. The graph below shows the wider Nawton area population trend line increasing at a steeper angle than the local traffic trends line.

What is being suggested in the new DC policy is that the location of a suburban stand-alone 3-bedroom dwelling on a 650m2 section places an equivalent demand on services as a 3-bedroom dwelling in a higher-density urban area. This is where the definition of “high-density” may be clouding assumptions. It is possible that high-density (such as High Rise) has greater costs than suburban density, but urban density is debatable.

The traditional traffic assumption is that a new suburban “3-bedroom dwelling equals 10 traffic movements per day”. The proposed 2018 DC policy (p42) for 2-bedroom and 1-bedroom dwellings uses “Residential Conversion Factors – Two Bedroom – Factor = 0.689 & One Bedroom – Factor = 0.477” (p41), which rounds up to 7 and 5 traffic movements per day respectively.

This next graph measures, as percentages, the wider Hamilton East area population growth vs traffic actual vs traffic predicted.

The above graph includes the actual and predicted Ruakura/Peachgrove intersection counts. We should note that the development of Hilda Ross retirement village occurred around 2002, quickly followed by Ruakura/Peachgrove/Wairere road building. Once the construction work force left this area, traffic movements evaporated to a level below that in 2002, despite the 200-plus dwellings having been built at Hilda Ross village for about 450 people (census mesh block 0896002 & 0896402). Yet at its gate is an oversized road designed to cater for predicted phantom trips (see below for predicted traffic), which by design has a negative/deadly impact on safety for weaker road users in the area.

To Summarise: the wider Hamilton east area’s density increased from around 1,900 people per km2 (ppkm2) in 2001 to 2,200 ppkm2 in 2013. For Hilda Ross village, which is dominated by smaller dwellings, there is a population density of over 5,000 ppkm2. However, a negative effect on traffic movements appears to be measureable. Like the assumptions used to predict the 80,000 vpd for 2026, the 0.477 factor for 1 bedroom homes is an assumption, not a fact.

For more on one-bedroom dwellings, Hamilton City Library has Kol Peterson’s book Backdoor Revolution: The Definitive Guide to [Accessory Dwelling Unit] ADU Development

The following excerpt is from Chapter 9: Impacts on a City

“Space efficiency and location efficiency – In general … neighbourhoods that are walk-able, bike-able, or transit oriented … Residents in such neighbourhoods will tend to have dramatically fewer vehicle miles travelled in a year than US residents living elsewhere.”

Reference: Ruakura Peachgrove Noise AECOM Nov 2009 – page 84 – Table 9: Predicted 2026 Upgraded Traffic Volumes

 

Hamilton Population Projections

Many of Hamilton City Council’s past population projections have been within one percent of the current 2018-31 projection linear line (p42&p119), excluding the 2012-22 prediction:

2006-16 Long Term Plan (LTP) 2016 prediction of 159,600 (NZ census estimate 161,400): -1,800 [1.1%]

2009-19 LTP 2019 prediction of 166,500 (p34) current prediction 167,909 (p114): -1,409 [0.8%]

2009-19 LTP 2051 prediction of 242,000 (p34) is above current projection line

2012-22 LTP 2021 prediction of 150,000 (current prediction 171,606): -21,606 fail [14.4%]

2015-25 LTP 2045 prediction of 210,000 (p20) is below current projection line

The 2015-25 LTP also has predictions for rateable units:

2016 projected 56,600 units (p143), above actual 55,995* (p119) +605[1.0%]

2017 projected 57,053 units (p143), above actual 56,706* (p119) +347[0.8%]

*(all excluding not-rated) on Historical Benchmarking (p119) would expect this to be the same for 2015-25 LTP for benchmarking between plans.

Former 10-year Plans  10-year plan 2015-25

Draft 10-year plan 2018-28 from council agenda Dec 2017 (in Italic)

 

Looking back at council’s first District Scheme in 1963, it missed how attractive Hamilton was to new people. This was corrected with the 1973 District Scheme getting the 1981 projection bang on, while 1986 was 14% over. The 1991 Town Plan came closer at 5% below actual levels for 1996. The 2012 district plan (p26), which was based on 2001 census figures, estimated 2026 levels just below the census data projection line. The 2017 district plan uses Statistics NZ estimates dated June 2013 (p9) to estimate its 2031 population, which lands on the census date line.

 

Looking forward, the 2018-28 LTP does give warning on the long term risks of planning to the higher line Page 203

“External factors … there has been a modest downward revision to net migration and population growth forecasts nationwide, and this had a small effect on estimated underlying demand for new dwellings. … Over the longer term, if growth was to slow, this could present risks to Council, … all scenarios are based on University of Waikato’s National Institute of Demographic and Economic Analysis (NIDEA) Low which is a conservative growth projection when compared with the medium projection.

To conclude, city populations can and do change. Both New York’s Manhattan Island and Houston’s population grew from about 200,000 to 1,000,000 in a 50 year period, regardless of whether that growth was outwards or upwards in terms of actual building.

http://hamiltonurbanblog.co.nz/2014/05/hamilton-urban-area-and-houston-urban-area/

References:

1963 – City of Hamilton District Scheme – NZ711-409-931-151-HAM (70-page A5 format)

1973 – City of Hamilton District Scheme – REF-S-711-409-931-151-HAM (37-page A5 format)

1981 – City of Hamilton District Scheme  – REF-S-711-409-931-151-HAM (89-page A4 format)

1991 – City of Hamilton Town Plan – REF-S-711-409-931-151-HAM (315-page A4 format plus appendices)