Archive for December, 2010

Full scale Noah’s ark in Hong Kong

December 6, 2010

That’s a pretty big boat. Check it out from satellite on google maps.

 

Earthquake repairs in South New Brighton

December 5, 2010

Possibly new flood management rules could effect our earthquake repairs, as South New Brighton is in a flood management area.

Resource consents, earthquake damaged buildings

Christchurch City Council have signalled that new flood management rules (introduced by way of Variation 48) are likely to  come into effect in early 2011. These rules affect new buildings, alterations to buildings and earthworks in identified flood management areas.

As a number of flood management areas have been badly affected by the earthquake and are likely to require extensive rebuilding works, a significant proportion of earthquake recovery work will now require resource consent unless existing use rights can be demonstrated.   Where resource consent is required, new building works will typically require elevated floor levels.

Headsup-Nov2010

If you rebuild on exactly the same footprint as before, you may have existing use rights under the Resource Management Act to rebuild at the original floor level, so long as this is at or above the Building Act 2004 – 1 in 50 year flood level plus freeboard. (If the original floor level was below this, then the Building Act standard will prevail).

Headsup-2008, Variation 48

In “tidal” flood management areas the minimum floor level will be 11.8m above Council datum, which is 2.76m or so above mean sea level 1937. This is 400mm above the current Building Act minimum floor level. This 11.8m includes sea level rise out to the year 2100, as the life expectancy of buildings is generally in excess of 50 years.

Christchurch City Council FAQ, Building consents

The Council has a network of approximately 1000 Level Benchmarks across the City and these are available free of charge. These levels are in terms of the Christchurch City Council datum.

They are precisely levelled survey points fixed into permanent structures such as concrete steps, headwalls, kerbs etc. The levels of the Benchmarks are expressed in terms of a common datum. In the case of Christchurch City Council the Datum is known as Christchurch City Datum, the zero point being 9.04m below Mean Sea Level. The No 1 Benchmark is in the foyer of the Christchurch Cathedral.

It is vitally important in terms of flood levels and drainage systems to be able to establish the relative difference in level between any particular points. The system of Benchmarks that has been established over the City enables Surveyors, Engineers and Builders to establish design ground levels for subdivisions, invert levels for pipe work and floor levels for new buildings at any point in the City confident that they are working in terms of one datum without the need to go back the Cathedral starting point every time.

The history of Christchurch City Datum dates back to the 19th century and the early days of the Christchurch Drainage Board. The need for a common level datum was evident very early in the quest to control Christchurch’s drainage issues. An arbitrary figure of 50 feet (15.24m) was chosen for the No 1 Benchmark in the foyer of the Christchurch Cathedral. Its relationship to Mean Sea Level was determined later and showed that the floor of the Cathedral is only 20.33 feet or 6.20m, above sea level).

South New Brighton Survey Marks

LINZ mark close to our property
LINZ mark including mean sea level measurement