Publication - Consultation paper

Water Environment and Water Services (Scotland) Act 2003 implementation: environmental standards - consultation

Published: 23 Oct 2020
Directorate:
Environment and Forestry Directorate
Part of:
Environment and climate change
ISBN:
9781800042216

Consultation seeking views on our proposals for new or updated environmental standards for Scotland’s water environment, and updates to some of the assessment methods used for deriving such standards.

Water Environment and Water Services (Scotland) Act 2003 implementation: environmental standards - consultation
7. Loch morphology: bank protection

7. Loch morphology: bank protection

Recent work undertaken by SEPA has shown that the existing method used to assess the physical condition of lochs can overestimate the morphological impact of bank protection on some loch waterbodies. The new proposed method is to use a graduated impact rating which takes account of the shoreline characteristics and location of the pressure relative to the waterline.

The existing method is applied using the Lake MImAS tool, which calculates the morphological status of a waterbody using a range of impact ratings associated with different engineering activities and structures. The current impact ratings associated with bank protection (Table 7.1) take no account of the position of the works relative to the water's edge and the potentially variable levels of associated habitat damage.

This can lead to an over estimation of the impact associated with bank protection in both the current classification and when undertaking the environmental standards tests for licensing.

Table 7.1 Existing impact ratings for hard bank protection in lakes
Lake zone Lake type
Low alkalinity and very shallow Low alkalinity and shallow or deep Moderate alkalinity and very shallow Moderate alkalinity and shallow or deep High alkalinity and very shallow High alkalinity and shallow or deep
Shore zone impact ratings 0.6 0.6 0.6 0.6 0.41 0.41

In order to address this issue, a more flexible approach is proposed that will allow SEPA to select from a range of shore zone impact ratings the one that most accurately reflects the risk posed by individual sections of bank protection in their site-specific context. The range of impact ratings is shown in Table 7.2, and a description of the hard bank protection set back locations is provided in Table 7.3.

Table 7.2. Revised impact ratings for hard bank protection in lakes
Lake zone Impact rating consistent with status class indicated Lake type
Low alkalinity and very shallow Low alkalinity and shallow or deep Moderate alkalinity and very shallow Moderate alkalinity and shallow or deep High alkalinity and very shallow High alkalinity and shallow or deep
Shore zone impact ratings High 0.025 0.025 0.025 0.025 0.025 0.025
Good 0.1 0.1 0.1 0.1 0.1 0.1
Moderate 0.22 0.22 0.22 0.22 0.22 0.22
Poor 0.37 0.37 0.37 0.37 0.37 0.37
Bad 0.6 0.6 0.6 0.6 0.41 0.41
Table 7.3 Shore zone hard bank protection set back locations
Class Description
High status Hard bank protection well within the zone landward of the terrestrial riparian vegetation boundary
Good Hard bank protection on the landward side terrestrial riparian vegetation boundary.
Moderate Moderate space for littoral processes. Bank protection in the water-wards side of the terrestrial riparian vegetation line AND at least half (>=50%) of the width of the natural littoral zone is available for natural processes.
Poor Substantial reduction of space for littoral processes. Bank protection in the water-wards side of the terrestrial riparian vegetation line AND less than half (<50%) of the width of the natural littoral zone is available for natural processes.
Bad Hard bank protection goes down into the water

Implications of the proposal

The proposed revised loch morphological standards for hard bank protection require additional survey information in order to select the correct impact rating. In most cases, this information is not currently available. Hence, the existing rating will continue to be used until the required information becomes available.

SEPA will seek the information required to apply the proposed new loch morphology standards as part of all new relevant licence applications. This will ensure that loch shoreline developments are assessed more accurately in future. Application of the more flexible proposed approach is always likely to lead to an improvement in condition and any regulatory impacts are, therefore, expected to be minimal.


Contact

Email: eqce@gov.scot