Stormwaters

Climate Change Rainfall for use in Sewerage Design - Design Storm Profiles, Antecedent Conditions, RedUp Tool Update and Seasonality Impacts - Guidance

Reference: 22/CL/10/19 - (1)
ISBN: 978-1-84057-956-7
Published Date: 01/01/2099

Climate Change Rainfall for use in Sewerage Design - Design Storm Profiles, Antecedent Conditions, RED-UPTool Update and Seasonality Impacts

Guidance

Price: £10  

Climate Change Rainfall for use in Sewerage Design - Design Storm Profiles, Antecedent Conditions, Red-Up Tool Update and Seasonality Impacts

Reference: 22/CL/10/19
ISBN: 978-1-84057-956-7
Published Date: 06/12/2022

With the first round of the Drainage and Wastewater Management Plans (DWMPs) being produced and increasing industry attention on storm overflows it is important to include the latest climate science in predictions of future rainfall intensities and patterns. This is so that the operators of urban drainage systems can predict and plan for future flooding and pollution risks. The water industry needs updated tools and specific guidance on how to apply this information in readiness for the PR24 planning (in England and Wales) and likely mandatory second cycle DWMPs.

This UKWIR project led by JBA Consulting with Stantec and Newcastle University has developed:

  • an updated version of the RED-UP tool, a time series perturbation tool that allows historic rainfall data to be perturbed to be representative of future climate. This version of RED-UP (3.0) supersedes the previous version developed in 2019.
  • six experimental new profiles for design rainfall.
  • a method of calculating catchment specific future design NAPI values using a climate perturbed rainfall time series together with projected potential evapotranspiration data for the corresponding climate epoch.

 

 

Price: £250  

Rainfall Intensity for Sewer Design - Technical Guide

Reference: 15/CL/10/16-1
ISBN: 184057 771 1
Published Date: 06/07/2015

UK water and sewerage companies do not have a way of assessing the growing risk of customer flooding and pollution from CSOs. Previous research for UKWIR used UKCIP02 and UKCP09 projections and data. However, short-period rainfall statistics used to assess existing and new sewer systems are largely the result of convective rainfall.  Convective rainfall processes are not well simulated by Regional Climate Models (used in UKCP09 and predecessor projections).
Addressing this issue, this project has produced estimates of rainfall intensity change over different parts of the UK using a combination of climate analogue data and a high-resolution (1.5km) climate model developed by the UK Met Office both approaches capturing or resolving convective rainfall events. The resultant rainfall intensity change estimates are, in general, higher than existing UK guidance suggests.

Sewer flooding frequency and volume, and frequency of pollution events are also investigated for five locations; indicating that these are also likely to increase in the future. It is recommended that further work is undertaken to add confidence to the results produced and to inform future UK guidance.

Price: £10