Planning objectives

Developing planning objectives is an important early step in the process for Drainage and Wastewater Management Plans (DWMPs). The planning objectives enable us to consider and identify the issues that we, and the organisations we are working with, care about in each river basin catchment, such as flooding and pollution.

Planning objectives are used in the DWMP process to assess the current and future performance of the drainage and wastewater systems, and identify where action and/or future investment is required. The performance is considered as a risk to failure that could have an impact on people and/or the environment.

The planning objectives are developed at the beginning of the DWMP during the strategic context stage. They are then used throughout the development of the DWMPs, especially for the Baseline Risk and Vulnerability Assessment (BRAVA) stage and the problem characterisation and programme appraisal.

Six planning objectives have been defined by Water UK for all water companies to use within their DWMPs, and report on nationally. The six common, national planning objectives are:

  1. Internal sewer flooding risk – which is internal flooding of a domestic or business premises by wastewater
  2. Pollution risk – pollution from any wastewater source on land or in water
  3. Sewer collapses risk
  4. Risk of sewer flooding in a 1 in 50 year storm – this is a severe storm that is likely to occur once in every 50 years or, put another way, a 2% chance of happening in any 12 month period
  5. Storm overflow performance – this is non-compliance of a storm overflow with the permit issued by the Environment Agency which specifies the amount, frequency and concentration allowed to be discharged into the receiving water
  6. Risk of WTW quality compliance failure – this is non-compliance of a Wastewater Treatment Works (WTWs) with its permit

We have identified two further planning objectives which will help us identify where we have current and future risks. The first is on the capacity of sewers and the second relates to the capacity of treatment works being exceeded as a result of new development (growth) and urban creep (paving over of land and additional connections into the sewer network). These are:

  1. Annualised Flood Risk (or hydraulic overload). This is the flood risk arising from different severities of rainfall
  2. WTW Compliance with the EA’s permit relating to the dry weather flow (DWF) arriving at the treatment works

In September 2020 we held a workshop with partner organisations in each river basin catchment. The purpose of the workshops was to discuss the need for any additional planning objectives to reflect any concerns or local issues from ourselves and partner organisations. The table below sets out the additional planning objectives proposed for each catchment.

Additional planning objectives


We completed an assessment of the proposed additional objectives identified at the workshops to:

  • understand which objectives are common across our entire region
  • identify which objectives should be considered further for inclusion in the first round of the DWMPs.

We used the following criteria to make the assessment:

  1. Data is readily available and the method for the risk assessment would be relatively straightforward: These will be explored further for inclusion in round 1 of the DWMP.
  2. Data is not readily available or the method for an assessment will be complex and take time to develop: These will be deferred to future rounds of the DWMP.
  3. Whether the proposed objective is a generic aim rather than an indicator of current and future performance so will not be included as a planning objective but will be reflected elsewhere in the DWMP.
  4. Whether it is already included in the existing Water UK planning objectives, or they can be easily modified to include the objective.

Through our assessment, we identified six additional planning objectives that will be included in the first round of the DWMPs:

  1. Achieve Good Ecological Status or Good Ecological Potential (GES/GEP)
  2. Improve surface water management and reduce surface water flooding
  3. Secure nutrient neutrality
  4. Reduce groundwater pollution
  5. Improve bathing waters
  6. Protect shellfish waters

We will apply these six planning objectives to all the river basin catchments across our whole operating area.
We have developed the BRAVA methodology for each of the objectives by working with our experts and those from our partner organisations. The results are available on our website.

Baseline Risk and Vulnerability Assessment


This work means we are able to include the additional objectives within the ‘Problem Characterisation’ and ‘Options Development and Appraisal’ stages of the DWMP.

We considered the remaining objectives and concluded that:

  • Reducing CSO discharges, pollution risk in the Marine Conservation Zone, the cumulative impacts of discharges to the Estuaries and flooding due to tide locking, are already included in the Water UK objectives and will be progressed in the first round of the DWMPs.
  • Increasing natural capital and water reuse and recycling, and achieving biodiversity net gain and carbon neutrality are among our long-term aims and will be considered in our DWMPs and business plans, especially when identifying investment choices.
  • Reducing the failure of pumping stations is an ongoing activity for our operational teams, and future risks are identified as part of our DWMP resilience assessment.
  • Increasing the separation of surface water from foul has been incorporated within ‘improve surface water management’ and adopted as an objective.
  • Understanding the impact of coastal erosion on our assets has been deferred to the next round of DWMPs. This will allow us to work with the Environment Agency and local councils to obtain data on predicted rates of coastal erosion and develop a robust methodology for an assessment of current and future risks.
  • We need to gather more data on the impact of effluent on receiving water bodies before we can progress the proposed objective to improve effluent quality during dry weather so have deferred this until the data is available.
  • We have deferred the objective to reduce the impact of plastics and chemicals until the UK Water Industry Research (UKWIR) programme reports its findings. It is a generic long-term objective for our industry.
  • Reducing misconnections is already a key focus for us with a new Misconnections Team providing significant input to our Bathing Waters improvement programme. However, it is not an objective we can achieve alone and, as part of the DWMP process, we have identified local hotspots and will target these and work with partner organisations to run campaigns to improve our customers’ understanding of the issue and change behaviours.

There are a few other areas such as aligning the DWMP with Defra’s 25 year Environment Strategy objectives and finding innovative solutions that address multiple issues are generic aims. We cannot complete a BRAVA for these as set out in the Water UK guidance on DWMPs, so they are not included as planning objectives. However, we support the Government’s strategy and the need to find innovative solutions so we will look for opportunities to both these things as we develop the DWMPs.

Published December 2020 and updated March 2021.

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