The objective of the project was to reduce risk to the public by identifying unsafe catchpit and manhole covers. For Auckland Council this is a highly sensitive and emotive topic following the death in 2017 of a 17 year old girl in a road catchpit in Favona and the second death of its kind in New Zealand. The starting point to reduce risk was to map the type and location of catchpits and manhole covers as the basis for further decision making. For example, during the project more than 24 different catchpit designs were identified. Auckland Council implemented a four-stage project review of the safety of catchpits and manhole covers across the region. We completed this review under the Auckland Council Healthy Waters Master Services Agreement. The staged approach comprised of the following;
- Technical overview of the road catchpit involved in this and other incidents, a review of Auckland Council and Auckland Transport policies, technical standards and practices, and the development of best practice safety practices
- Assessment of the public health and safety risks from stormwater catchpits and manholes
- Catchpit Risk Assessment Tool development
- Catchpit Safety Review - a review of the outcomes from recommendations made as part of Stages 1-3 and stormwater manhole safety initiatives.
OUR SOLUTION
We embraced best practice and innovation to deliver operational efficiency. This required developing a picture of national and international best practice, assessing current standards and practices against this and making relevant recommendations. We used a bespoke location specific GIS based Catchpit Risk Assessment tool, based on a wide range of different variables and risks. This enabled us to produce a prioritised risk-based asset intervention list. Along with this, we incorporated its review on current Auckland Council initiatives to improve safety around stormwater manholes, including IOT sensors, manhole surcharging assessments, criticality model and lid retrofitting methodology.
OUTCOME/CLIENT BENEFITS
Identification of high risk locations and assets has enabled Auckland Council to prioritise interventions and asset investment plans. This enables Council to proactively reduce risk and provide value for money with public funds. On the basis of our review, Auckland Council ran a three-month pilot programme which educated on catchpit risks and safety. This has led to a 30% increase in the reporting of water safety issues, leading to improvements in public safety.
LIST OF PRIMARY SERVICES
Under Stage 1 we researched and reviewed previous catchpit safety incidents national and internationally, as well as review of current best safety practice and relevant policies and technical standards. The Stage 1 review found that Auckland Council and Auckland Transport are managing public safety around catchpits in a similar manner relative to other local authorities around New Zealand, and internationally. We identified that drowning at catchpits is an extremely rare occurrence, however it was identified that a risk assessment should be undertaken to assess the risk of drowning against other catchpit health and safety risks.
During Stage 2 we undertook an assessment of public and user health and safety risks from stormwater catchpits. We reviewed the existing controls currently used to address these risks. We identified and reviewed potential safety interventions / modifications and provide recommendations for improvements to catchpit safety (where applicable) to address residual risks which may require further action. The outcome of the review was a number of recommendations to mitigate the risks from public access to catchpit based on identification and evaluation of additional controls against the relative benefits and constraints.
We also identified the benefits of Auckland Council updating their existing safety assessment tool to identify if there are any catchpits where there is a higher risk to the public. This can then be used to enable prioritisation and undertake a feasibility assessment of retrofitting interventions. Stage 3 was the development of a GIS based Catchpit Risk Assessment Tool and methodology, updating the existing Auckland Council safety assessment tool. This will then be used to identify if there are any catchpits where there is a higher risk to the public. The tool is intended to enable prioritisation of further feasibility assessments of retrofitting interventions and infrastructure investment needs.
Stage 4, currently underway, is a review of the progress on outcomes and recommendation made across stages 1-3 related to catchpits. It also involves reviewing, reporting and making recommendations on current Auckland Council initiatives to improve safety around stormwater manholes, including IOT sensors, manhole surcharging assessments, criticality model and lid retrofitting methodology
KEY FACTS
We discovered that there are 24 'standard' catchpit designs in use in New Zealand.
