Representation by Ouse & Derwent Internal Drainage Board (Ouse & Derwent Internal Drainage Board)
- Date submitted
- 4 March 2024
- Submitted by
- Other statutory consultees
Part of the Grid Connection Corridor is within the district for Ouse & Derwent Internal Drainage Board. Our district sits between the River Derwent and the River Ouse around Babthorpe and Hemingbrough. Our comments therefore relate solely to the Grid Connection Corridor within that area. Under the Land Drainage Act 1991 and the Boards’ byelaws, the Board’s prior written consent (outside of the planning process) is needed for:- a. any connection into a Board maintained watercourse, or any ordinary watercourse in the Board’s district. b. any discharge, or change in the rate of discharge, into a Board maintained watercourse, or any ordinary watercourse in the Board’s district. This applies whether the discharge enters the watercourse either directly or indirectly (i.e. via a third party asset such as a mains sewer). c. works within or over a Board maintained watercourse, or any ordinary watercourse in the Board’s district – for example, land drainage, an outfall structure, bridges, culverting etc. d. any proposed works or structures in, under, over or within 9 metres of the top of the bank of any “Board maintained watercourse”. Please note that the Board does not, generally, own any watercourses and the requirement to obtain the Board’s consent is in addition to obtaining consent from any land owner or other authority to carry out the relevant works. Using the “Environmental Statement – Figure 9-2 – Drain Names – Sheet 3 of 3”, the Board will be looking at the below watercourses which may/will be effected: 1. Drain DE21 – this is the Board maintained watercourse known as Loftsome Bridge Drain. 2. Drain DE53 - this is the Board maintained watercourse known as Bishops Clough Drain. The Board’s pumping station is downstream, prior to the outfall into the River Derwent. 3. Drain DE52 – this is an ordinary watercourse not maintained by the Board but by the riparian owner. 4. Drain DE03 – this is an ordinary watercourse not maintained by the Board but by the riparian owner. The Board’s understanding is that there are no drainage requirements along the Grid Connection Corridor. The Board will therefore be looking at: 1. cables crossing any watercourses within our district; and 2. access road crossings over watercourses within our district. ------------------------------------------------------------------- CABLE CROSSINGS The Environmental Statement, Chapter 9, states: “9.4.4 All cables will be installed a minimum of 1.5 m below the bed of watercourses (excluding the River Ouse and River Derwent). … The minimum installation depth of 1.5 m for Featherbed Drain, DE53 and Loftsome Bridge Drain will ensure that the channel is not disturbed or risk being exposed by future bed scour.” With regards to the proposed Horizontal Directional Drilling, the Environmental Statement, Chapter 9, states: “9.6.23 The sections of the cables that will be installed via trenchless approaches will require send and receive pits to be installed at each crossing point. … The send and receive pit excavations for drilling/boring will be located at least 10 m from the watercourse edge, as measured from the top of bank (or 16 m from the landward toe of flood defences). This may require survey work (prior to construction) in some locations to adequately define and agree the top of bank position.” The Board notes that the applicant is proposing Horizontal Directional Drilling for both DE21 and DE53. The principle of this is agreed. The Environmental Statement, Chapter 9, states: “9.4.5 As a worst case for the assessment, it is assumed that all other watercourses crossings required for cables would be installed using an open cut technique. This is considered a reasonable worst-case assumption and follows a precautionary approach. 9.4.6 Where intrusive crossings of small watercourses are required, it is assumed that water flow would be maintained by temporarily damming the watercourse and either over pumping or fluming the flow through the works. The final crossing proposals for watercourses cable installation will be determined at the detailed design stage post-consent…” Open cut crossings are potentially proposed for Drain DE52 and Drain DE03. The Board would prefer the use of Horizontal Directional Drilling for these watercourses but if this is not possible, we shall await specific details in due course. ------------------------------------------------------------------- ACCESS ROAD CROSSINGS The Environmental Statement, Chapter 9, states: “9.6.34 … a temporary open span bridge is to be installed to facilitate the construction of the Grid Connection Corridor on Drain DE53 at NGR SE 69239 29218. Bridge foundations would again be set back from the edge of the channel to ensure continuity of riparian habitat.” There only appears to be one potential access road crossing within the Board’s district. This is a new open span bridge on Drain DE53. The Board has no objection to the principle of this new bridge. Our initial comments would be: 1. There must be sufficient distance between the proposed bridge and our pumping station downstream. 2. Given that this is a temporary crossing, then provided the landowner is happy with the bridge foundations being set more landward (rather than on the bank top), the Board are satisfied in this regard also. ------------------------------------------------------------------- DRAFT DEVELOPMENT CONSENT ORDER The Board notes that Article 6 of the draft Development Consent Order is disapplying sections 23 and 32 of the Land Drainage Act 1991, together with any Byelaws that the Board has made under Section 66 of the Land Drainage Act 1991. Instead, Article 43 states that Schedule 14 (the Protective Provisions) have effect. Part 3 of Schedule 14 is relevant to the Board. Article 16 relates to the discharge of surface water. Article 16(5) states that the protection provisions apply where the drain “belongs or under the control of a drainage authority”. The Board does not “own” any watercourses and we do not maintain all watercourses in our district. Under our Byelaws, the Board’s prior written consent is however needed for any discharge of water into any watercourse within our district (whether it is Board maintained or not). We would therefore ask that it is made clear that Article 16(5) includes any watercourse within the district of a drainage authority. With regards to Part 3 of Schedule 14 of the draft Development Consent Order, the Board are in agreement with these provisions other than: a) ““specified work” means so much of the authorised development as is in, on, under, over or within 8 metres of a drainage work or is otherwise likely to affect the flow of water in any watercourse.” The Board would ask that this is amended to 9 metres and would like to specifically note that if it is a watercourse, for example, we would be looking at 9 metres from the bank top and would not measure from the water’s edge or centre of the watercourse. b) Please can we have a similar provision to that provided to the Environment Agency at paragraph 51 of Schedule 14. The Board would request: “If by reason of construction of the specified work the drainage authority’s access to an ordinary watercourse is materially obstructed, the undertaker must provide an alternative means of access as soon as reasonably practicable to allow the drainage authority to maintain the ordinary watercourse.”