Water Supply Rectification
20
Aug

Water Supply Rectification

There has been a growing number in recent years of water supply rectification cases here in NZ. Yet these have been what were previously compliant, approved, and signed off sprinkler systems.

How has this come about?

There are usually two main reasons why this has become an issue. One of these is out of your control. And the other is generally because the building(s) are no longer being used for their original intended purpose.

The first reason is “My towns main supply has been reduced”.

Understanding why your towns main has been reduced and what you can do about it will in a nutshell leave you in the same position as where you were when you asked the question being “My towns main is still reduced”. How can i rectify it and what are the legal requirements from council to provide me with sufficient water supply.

All New Zealand Council’s need to comply with SNZ/PAS 4509:2008: New Zealand Fire Service Fire Fighting Water Supplies Code of Practice. With the clarification that the minimum flow for a single hydrant shall be 25 litres/second with a residual pressure of 100 kPa in the towns main. Also to any additional requirement in their district plan.

We have been engaged by many building owners, consultants and contractors to have meetings with multiple councils throughout NZ. And to be frank when it comes down to “When will the supply be increased” or “You have dropped the pressure resulting in a potential million dollar issue”, we have the same line thrown back at us. We only have to supply 100 kPa.

Change of Use

If you have changed your building use or storage within your building(s) it is a little bit easier to swallow. Understanding that some guidance may not have been given at the time of this change. There are likely significant implications to your building and the requirement of a sprinkler system or the modification to your existing sprinkler system to cater for this.

An example is where you have received a letter from council stating their intentions to reduce the towns main pressure. Council states that this may have an impact on your sprinkler system and that you should contact your service provider.

Another example is that you have just had an annual / biennial sprinkler survey conducted. Subsequently you receive a report with a major deficiency item noting that your water supply is not adequate, or that your storage is not within its intended design parameters.

Finding a solution.

Finding a solution and rectifying it can be done in numerous ways. Firstly, you should understand what your sprinkler system is and what your liabilities are now that you have been issued with such a document stating that you have or may potentially have in the future a deficient supply.

Your sprinkler system is a specified system and is a listed feature on your building warrant of fitness. This system will also be part of your compliance schedule and its deficiency may have been identified through one of its routine tests outlined within this document. All of this forms part of your compliance for your building and ensuring your peoples safety, your business and its assets are protected and maintained accurately in terms of this specified system.

Your specified system is no longer compliant and this will have an effect that needs to be rectified. Normally the first thing people think is that “Are my building/s covered by insurance”. However, the question that should be asked is “Is my system being used as safe access and egress for my people and or fire fighters if a fire was to occur”. These are all building and system specific, however you need to understand the gravity of the deficiency and its implications. You should also consult with a fire protection designer to work out “What is my solution”.

Solutions.

Potential solutions vary and not all water supply issues are as drastic as some people think. It is about looking at each case individually and working from the basics up.

An example of a best case scenario, is having a third party inspection agency complete a water supply flow test. This test is carried out as part of the sprinkler systems biannual survey. The survey found to have a deficient water supply.

Its solution was to open a valve that had been shut two streets away. The valve was isolated to enable a replacement piece of underground main to that street. How we got there was the same process that we follow that may lead to worse case scenario where your building may not be able to be protected based on its use.

The one step back from this may be reduced ceiling heights or reduced storage heights. Or installation of duplicate pumps, a water storage tank and or modification to an existing system.

A significant amount of our solutions arise from drawing the existing system and completing hydraulic calculations. And as a result, this enables us to work out its maximum potential before looking at any changes.

Identifying where your water supply rectification issue is from best case to worse case follows a specific set of steps we have created to identify the best solution for your needs. We also look at what your potential needs may be in the future to accommodate any planned developments.

If you would like to discuss a water supply rectification issue please get in contact with us by clicking here .