WORKS PROGRAMMES 2018/19
The Boards proactively exercise their permissive Powers under the Land Drainage Act 1991 (amended 1994) to carry out maintenance on the main network of important watercourses vested under them in the Drainage District. The Boards classify their networks into: high risk (category 1), medium risk (category 2), and low risk (category 3) watercourses, such that it can prioritise its maintenance programme on the watercourses where the consequence of flooding is significant and the benefit from maintenance is greatest. There is also a sub-category of high risk watercourses (Category 1A), whereby the Boards consider these watercourses critical to managing flood risk to especially vulnerable areas, and maintenance may be carried out at any time of the year, if it is in the interest of overriding public need and in accordance with the Drainage Channel Biodiversity manual produced by the Association of Drainage Authorities and Natural England.
The Boards aim to undertake a rolling programme of asset inspections, as resources allow. Watercourses are inspected by the Boards’ asset surveyors, assessed for overall condition and recorded into the individual Board’s Asset Management System. This information is then used to identify the watercourses most in need of maintenance and for the development of the annual maintenance programme.
As the Boards aim to carry out essential watercourse maintenance on the high risk category 1 watercourses each year, they are maintained in good condition to reflect the consequences from flooding. The current watercourse condition inspection regime is prioritising medium risk category 2 watercourses, followed by low risk category 3 watercourses to better develop and inform the future three-year maintenance programme.
The individual Board’s map identifies the proposed watercourse indicative maintenance programme for 2018/19.
The high risk (category 1) watercourses are normally maintained annually, which typically involves clearing blockages and obstructions, flailing and weed control, as appropriate. These watercourses are maintained in a good functional standard to minimise flood risk.
The medium risk (category 2) watercourses are maintained on a rolling needs-basis programme. Historically, the Boards aimed to maintain these on a five year cycle. The current programme is based on a slightly more frequent cycle, primarily to carry out flailing of the watercourse banks, with the aim of keeping the overall condition of the watercourse in better condition by reducing the risk of heavy vegetation growth, thus reducing the need for time consuming clearance works and providing long term economic and efficiency benefits.
The low risk (category 3) watercourses are maintained based on their condition and priority, so are maintained on a much lower frequency than the high and medium risk watercourses. Some watercourses may proactively not be maintained for conservation benefit, providing the risk of flooding is acceptable.
The Boards will consider ‘requests for maintenance’ where specific drainage problems are experienced.
If you would like further information or to discuss the current or future maintenance programmes please contact the Boards’ engineering team on 01234 767995 or firstname.lastname@example.org.
Trash Screen Inspection Regime and Emergency Works
The Boards’ asset inspectors also carry out a monthly check on a schedule of culverts, trash screens and locations identified as being prone to blockage and flooding. Minor obstructions and light debris are cleared by the inspectors to minimize the demand on resources. More significant amounts of debris are reported for either the workforce to clear or to the relevant authority responsible for the asset to action.