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ANNEX 6: SURFACE WATER MORPHOLOGICAL CONDITION LIMITS - PROPOSED CONDITION LIMITS FOR FRESHWATER AND BRACKISH LOCHS
1. To determine the relative hazard posed to the morphological characteristics of:
(i) a loch's shore zone; or
(ii) a loch excluding its shore zone
by the different morphological alterations specified in Table D below, SEPA shall classify the loch or part thereof, as being of the Type specified in Column 2, 3 or 4 of Table C below which corresponds to the applicable geological and depth characteristics of the loch or part.
2. To determine the geological and depth characteristics of a loch or any part thereof and subject to paragraphs 3 and 4 below, SEPA shall classify-
(i) all brackish lochs as being of the geological category; "high alkalinity";
(ii) a freshwater lochs as being of the geological category specified in Column 1 of Table A which corresponds with the annual mean alkalinity range specified in Column 2 of that Table which is applicable to the loch; and
(iii) the depth characteristics of the loch as being of the depth category specified in Column 1 of Table B which corresponds with the depth range specified in Column 2 of that Table which is applicable to the loch.
3. Where SEPA has insufficient data to classify the geological characteristics of a freshwater loch in accordance with the procedure set out in sub-paragraph (ii) of paragraph 2, it shall classify the geological characteristics of the loch as being of the geological category specified in Column 1 of Table A which corresponds with the annual mean conductivity range specified in Column 3 of that Table which is applicable to the loch.
4. Where SEPA has insufficient data to classify the geological characteristics of a freshwater loch using the criteria set out in paragraphs 2 or 3 above, it shall classify the geological characteristics of the loch as being of the geological category specified in Column 1 of Table A which corresponds with the description of the solid geology of the catchment of the loch specified in Column 4 of that Table which is applicable to the loch.
5. For the purposes of paragraph 9 below, SEPA shall determine the magnitude of each applicable alteration listed in column 1 of Table D below using the corresponding measure of the magnitude of the alteration specified in column 2 of that Table.
6. Where a range is given for a measure of the magnitude of an alteration in Column 2 of Table D below, SEPA shall assign a value for the magnitude of the alteration which falls within the applicable range and which, in the opinion of SEPA, reflects the spatial extent of influence of the alteration on the shore zone, or part thereof, or on the rest of loch or part thereof.
7. For each applicable alteration specified in Column 1 of Table E and Column 1 of Table F, SEPA shall assign the relative hazard scores corresponding to the loch type listed in column 2, 3, 4, 5, 6 or 7 of Tables E and F into which the loch or part, has been classified in accordance with paragraphs 1 to 4 above.
8. For the purposes of paragraph 7, where a range is given for a relative hazard score in Table E or F below, SEPA shall assign a score which falls within the applicable range and, which in the opinion of SEPA, reflects the severity of the alteration to the shore zone, or part thereof, or to the rest of loch or part thereof.
9. SEPA shall calculate the morphological condition values for the loch excluding the loch shore zone and for the shore zone of a loch or part thereof in accordance with the formulae-
and
respectively, where:
"A" = the hazard score for the loch excluding the shore zone, which applicable to the alteration in accordance with Table F;
"B" = the magnitude of the alteration determined in accordance with the measure of the magnitude of the alteration applicable to that alteration in accordance with Column 2 of Table D;
"C" = the hazard score for the loch shore zone, which is applicable to the alteration in accordance with Table E; and
"n" is the number of different alterations listed in Table D that are applicable to the loch or part thereof being assessed.
10. SEPA shall compare the morphological condition values for the loch or part thereof, excluding the shore zone, and for the shore zone of the loch or part calculated in accordance with paragraph 5 above, with the corresponding morphological condition limits for "high", "good", "moderate" and "poor" specified in Columns 2, 3, 4 and 5 respectively of Table G below.
Table A: Geological characteristics used to identify geological categories to which the morphological conditions for freshwater and brackish lochs apply
Column 1 | Column 2 | Column 3 | Column 4 |
|---|
Geological category | Annual mean alkalinity | Annual mean conductivity | Solid geology of the catchment of the [lake] |
| Micro-equivalents per litre | Micro Siemens per centimetre | % of catchment |
Low alkalinity | < 200 | = 70 | > 90 % siliceous |
Moderate alkalinity | 200 - 1000 | > 70 - 250 | > 50 % siliceous and = 90 % siliceous |
High alkalinity | > 1000 | > 250 | > 50 % calcareous |
Table B: Depth characteristics used in identifying the loch types to which the loch morphological condition limits apply
Column 1 | Column 2 |
|---|
Depth category | Mean depth (metres) |
Very shallow | < 3 |
Shallow | 3 - 15 |
Deep | > 15 |
Table C: Types to which the morphological condition limits for lochs apply
Column 1 | Column 2 | Column 3 | Column 4 |
|---|
Lake depth characteristics | Loch alkalinity characteristics |
Low alkalinity | Moderate alkalinity | High alkalinity |
Very shallow | Type I | Type III | Type V |
Shallow | Type II | Type IV | Type VI |
Deep | Type II | Type IV | Type VI |
Table D: Morphological alterations to which the morphological condition limits for lochs apply
Column 1 | Column 2 |
|---|
Morphological alteration | Measure of the magnitude of alteration |
1. Impounding works or works causing the lowering of the river bed immediately downstream of the loch outlet. | 2 - 20 |
2. Bank revetment using materials other than vegetation; geotextiles; or soil. | (length of bank revetment in metres) ÷ (total length in metres of the loch shore or part thereof) |
3. Bank revetment using vegetation; geotextiles; or soil. | (length of bank revetment in metres) ÷ (total length in metres of the loch shore or part thereof) |
4. Any structure on the bed of a loch that extends from the shore into the loch other than an outfall, pipe, cable or part of a structure referred to in alteration 1, 5 or 6. | (length of structure in metres) ÷ (total length in metres of the loch shore or part thereof) |
5. Any structure which: (i) is suspended above the surface of a loch between foundation structures on the bed of the loch; and (ii) extends from the shore out into the loch. | (length of structure in metres) ÷ (total length in metres of the loch shore or part thereof) |
6. In-filling by any means of a part of a loch with the effect of extending the adjacent terrestrial land surface into the area previously occupied by loch water. | (area infilled in metres 2) ÷ (total area in metres 2 of loch bed or part thereof included in assessment) |
7. Depositing of any material containing bedrock, boulders, gravel, sand, silt, mud or any mixture thereof on the bed of a loch other than as part of alterations 1, 2, 3, 4, 5 or 6. | (area of lake bed in metres 2 occupied by such material) ÷ (total area in metres 2 of loch bed or part thereof included in assessment) |
8. Removal of bed material by excavation from the bed of a loch. | (area of lake bed in metres 2 from which bed material is removed) ÷ (total area in metres 2 of loch bed or part thereof included in assessment) |
9. Alteration of the structural complexity of vegetation on land within 10 metres of the loch edge, ranging from complete removal of vegetation and replacement with impermeable surfaces to a partial change to the density of a structural component of the vegetation. | 0 - 15 |
Note to Table D
Where it considers that:
(i) alterations to the shore zone resulting from recreational activities;
(ii) alterations to the shore zone or other parts of a loch resulting from boat moorings in, or on, the loch bed;
(iii) alterations to the shore zone or other parts of a loch resulting from the removal of aquatic vegetation from the loch;
(iv) alterations to the shore zone or other parts of a loch resulting from floating tethered structures on the loch;
(v) alterations to the shore zone or other parts of a loch resulting from the effect on water flows and sediment transport into the loch of upstream impounding works;
(vi) alterations to the shore zone or other parts of a loch resulting from the effect on water flows and sediment transport into the loch of land uses within the catchment of the loch; or
(vii) alterations falling under alteration 4 or 5 above that impound water or partly or completely curtail water exchange between opposite sides of the structure
pose a significant risk (on their own or in combination with other alterations) to the ecological quality of a loch or part thereof, SEPA may:
(a) identify the appropriate hazard scores for the alteration which, in its judgement, reflects the relative hazard posed by the alteration, taking account of the loch type concerned and relevant scientific advice;
(b) identify an appropriate measure for the magnitude of the alteration; and
(c) include consideration of the alteration in calculating the morphological condition values for the loch or part in accordance with paragraph 9 above.
Table E: Relative hazard posed by different morphological alterations to the loch shore zone
Morphological alteration (i) | Loch types to which the morphological conditions limits apply |
|---|
Column 1 | Column 2 | Column 3 | Column 4 | Column 5 | Column 6 | Column 7 |
|---|
| Type I | Type II | Type III | Type IV | Type V | Type VI |
1 | 1.35 - 2.1 | 1.35 - 2.1 | 1.35 - 2.1 | 1.35 - 2.1 | 0.98 - 1.2 | 0.98 - 1.2 |
2 | 0.6 | 0.6 | 0.6 | 0.6 | 0.41 | 0.41 |
3 | 0.4 | 0.4 | 0.4 | 0.4 | 0.28 | 0.28 |
4 | 0.75 | 0.75 | 0.75 | 0.75 | 0.45 | 0.45 |
5 | 0.45 | 0.45 | 0.45 | 0.45 | 0.3 | 0.3 |
6 | 1.1 | 1.1 | 1.1 | 1.1 | 0.6 | 0.6 |
7 | 1.1 | 1.1 | 1.1 | 1.1 | 0.6 | 0.6 |
8 | 1.2 | 1.2 | 1.1 | 1.1 | 0.65 | 0.65 |
9 | 0.35 | 0.35 | 0.35 | 0.35 | 0.18 | 0.18 |
Note to Table E:
(i)The morphological alterations listed in Column 1 of Table E refer to the morphological alterations identified in accordance with Table D.
Table F: Relative hazard posed by different morphological alterations to parts of the loch other than the loch shore zone
Morphological alteration (i) | Loch types to which the morphological conditions limits apply |
|---|
Column 1 | Column 2 | Column 3 | Column 4 | Column 5 | Column 6 | Column 7 |
|---|
| Type I | Type II | Type III | Type IV | Type V | Type VI |
1 | 1.0 - 1.4 | 0.35 - 0.5 | 0.85 - 1.2 | 0.45 - 0.6 | 0.65 - 0.8 | 0.3 - 0.4 |
2 | 0.1 | 0 | 0.1 | 0 | 0.03 | 0 |
3 | 0.1 | 0 | 0.1 | 0 | 0.03 | 0 |
4 | 0.25 | 0.13 | 0.2 | 0.15 | 0.1 | 0.1 |
5 | 0.23 | 0.04 | 0.19 | 0.04 | 0.08 | 0.04 |
6 | 0.9 | 0.34 | 0.38 | 0.38 | 0.45 | 0.26 |
7 | 0.83 | 0.3 | 0.38 | 0.34 | 0.41 | 0.23 |
8 | 0.79 | 0.3 | 0.75 | 0.3 | 0.34 | 0.19 |
9 | 0.15 | 0.03 | 0.35 | 0.03 | 0.05 | 0.03 |
Note to Table F:
(i)The morphological alterations listed in Column 1 of Table F refer to the morphological alterations identified in accordance with Table D.
Table G: Morphological condition limits for freshwater and brackish lochs
Column 1 | Column 2 | Column 3 | Column 4 | Column 5 |
|---|
Loch zone | High | Good | Moderate | Poor |
|---|
Loch, excluding the shore zone | 0.05 | 0.15 | 0.30 | 0.45 |
|---|
Loch shore zone | 0.05 | 0.15 | 0.30 | 0.45 |
|---|
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