7. Modelling results
The results for each case study catchment and the national picture are given below. All figures are on a ‘per annum’ basis. Costs are itemised to show detail, then summed to give:
 Total onsite costs;
 Total off site costs (with drinking water costs);
 Total offsite costs (without drinking water costs);
 Total costs (with drinking water costs);
 Total costs (without drinking water costs).
At present, the Ugie is the only catchment where drinking water is abstracted (so incurring greater costs associated with water treatment). However, these costs have also been presented for the other 4 catchments, to reflect any future plans to abstract drinking water from these catchments
The annual costs of soil erosion in each catchment are given in Tables 33, 34, 35, 36 and 37 for the Ugie, Pow, Girvan, Esk and Tweed catchments respectively. Summary tables for all catchments are given in Table 38
Detailed tables of annual costs for the Ugie catchment (as an illustration) are shown in Appendix 9.
7.1. Catchment 1: Ugie
Table 33. Annual costs of soil erosion in the Ugie catchment
Physical data 
Total Catchment area (ha) 
29,878 
Total areas at risk within catchment (ha) 
3,632 
Proportion at risk (%) 
12% 
Soil depth loss (mm yr^{1}) 
0.29 
Catchment soil erosion (t yr^{1}) 
7,392 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.25 
Soil N loss (t yr^{1}) 
54 
Soil P loss (t yr^{1}) 
19 
Soil K loss (t yr^{1}) 
3 
Soil C loss (t yr^{1}) 
1077 
Onsite costs 
Total catchment productivity loss due to erosion (£) 
8,829 
Catchment productivity loss due to erosion in risk area (£ ha^{1} ) 
2.4 
Total catchment productivity loss due to erosion in total area (£ ha^{1} ) 
0.3 
Total catchment N loss cost due to erosion (£) 
36,328 
Average catchment N loss cost due to erosion (£ ha^{1} risk area) 
10 
Average catchment N loss cost due to erosion (£ ha^{1} category area) 
1.2 
Total catchment P loss cost due to erosion (£) 
13,076 
Average catchment P loss cost due to erosion (£ ha^{1} risk area) 
3.60 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.44 
Total catchment K loss cost due to erosion (£) 
1,329 
Average catchment K loss cost due to erosion (£ ha^{1} risk area) 
0.37 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.04 
Total catchment C loss cost due to erosion (£) 
718 
Average catchment C loss cost due to erosion (£ ha^{1} risk area) 
0.20 
Average catchment C loss cost due to erosion (£ ha^{1} category area) 
0.02 
Offsite costs 
Cost of sediment removal in rivers & canals (£) 
38,066 
Cost of sediment removal in drinking water (£) 
133,048 
Cost of N in rivers and lakes (£) 
10,302 
Cost of N in transitional waters (£) 
542 
Cost of N in drinking water (£) 
11,007 
Cost of P in freshwater lakes (£) 
31,902 
GHG cost of soil C loss (£) 
53,767 
Total costs 
Total onsite cost 
60,281 
Total offsite cost (with drinking water costs) 
278,634 
Total offsite cost (without drinking water cost) 
134,580 
Total costs with drinking water costs 
338,915 
Total costs without drinking water 
194,861 
Total cost / ha (without drinking water) (£ ha^{1} ) 
6.52 
Total cost / ha (with drinking water) (£ ha^{1} ) 
11.34 
7.2. Catchment 2: The Pow
Table 34. Annual costs of soil erosion in the Pow catchment
Physical data 
Total Catchment area (ha) 
4,332 
Total areas at risk within catchment (ha) 
511 
Proportion at risk (%) 
12% 
Soil depth loss (mm yr^{1}) 
0.21 
Catchment soil erosion (t yr^{1}) 
1,016 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.25 
Soil N loss (t yr^{1}) 
4 
Soil P loss (t yr^{1}) 
2 
Soil K loss (t yr^{1}) 
0 
Soil C loss (t yr^{1}) 
81 
Onsite costs 
Total catchment productivity loss due to erosion (£) 
1,042 
Catchment productivity loss due to erosion in risk area (£ ha^{1} ) 
2 
Total catchment productivity loss due to erosion in total area (£ ha^{1} ) 
0.2 
Total catchment N loss cost due to erosion (£) 
3,010 
Average catchment N loss cost due to erosion (£ ha^{1} risk area) 
6 
Average catchment N loss cost due to erosion (£ ha^{1} category area) 
0.7 
Total catchment P loss cost due to erosion (£) 
1,465 
Average catchment P loss cost due to erosion (£ ha^{1} risk area) 
2.86 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.34 
Total catchment K loss cost due to erosion (£) 
154 
Average catchment K loss cost due to erosion (£ ha^{1} risk area) 
0.30 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.04 
Total catchment C loss cost due to erosion (£) 
54 
Average catchment C loss cost due to erosion (£ ha^{1} risk area) 
0.11 
Average catchment C loss cost due to erosion (£ ha^{1} category area) 
0.01 
Offsite costs 
Cost of sediment removal in rivers & canals (£) 
5,230 
Cost of sediment removal in drinking water (£) 
18,280 
Cost of N in rivers and lakes (£) 
854 
Cost of N in transitional waters (£) 
45 
Cost of N in drinking water (£) 
912 
Cost of P in freshwater lakes (£) 
3,573 
GHG cost of soil C loss (£) 
4,059 
Total costs 
Total onsite cost 
5,724 
Total offsite cost (with drinking water costs) 
32,953 
Total offsite cost (without drinking water cost) 
13,761 
Total costs with drinking water costs 
38,677 
Total costs without drinking water 
19,485 
Total cost / ha (without drinking water) (£ ha^{1} ) 
4.50 
Total cost / ha (with drinking water) (£ ha^{1} ) 
8.93 
7.3. Catchment 3: Girvan
Table 35. Annual costs of soil erosion in the Girvan catchment
Physical data 
Total Catchment area (ha) 
23,393 
Total areas at risk within catchment (ha) 
3,533 
Proportion at risk (%) 
15% 
Soil depth loss (mm yr^{1}) 
0.20 
Catchment soil erosion (t yr^{1}) 
4,652 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.20 
Soil N loss (t yr^{1}) 
33 
Soil P loss (t yr^{1}) 
11 
Soil K loss (t yr^{1}) 
2 
Soil C loss (t yr^{1}) 
605 
Onsite costs 
Total catchment productivity loss due to erosion (£) 
4,236 
Catchment productivity loss due to erosion in risk area (£ ha^{1}) 
1.20 
Total catchment productivity loss due to erosion in total area (£ ha^{1}) 
0.18 
Total catchment N loss cost due to erosion (£) 
22,182 
Average catchment N loss cost due to erosion (£ ha^{1} risk area) 
6.28 
Average catchment N loss cost due to erosion (£ ha^{1} category area) 
0.95 
Total catchment P loss cost due to erosion (£) 
7,236 
Average catchment P loss cost due to erosion (£ ha^{1} risk area) 
2.05 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.31 
Total catchment K loss cost due to erosion (£) 
881 
Average catchment K loss cost due to erosion (£ ha^{1} risk area) 
0.25 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.04 
Total catchment C loss cost due to erosion (£) 
403 
Average catchment C loss cost due to erosion (£ ha^{1} risk area) 
0.11 
Average catchment C loss cost due to erosion (£ ha^{1} category area) 
0.02 
Offsite costs 
Cost of sediment removal in rivers & canals (£) 
23,959 
Cost of sediment removal in drinking water (£) 
83,740 
Cost of N in rivers and lakes (£) 
6,291 
Cost of N in transitional waters (£) 
331 
Cost of N in drinking water (£) 
6,721 
Cost of P in freshwater lakes (£) 
17,654 
GHG cost of soil C loss (£) 
30,187 
Total costs 
Total onsite cost 
34,939 
Total offsite cost (with drinking water costs) 
168,882 
Total offsite cost (without drinking water cost) 
78,421 
Total costs with drinking water costs 
203,821 
Total costs without drinking water 
113,360 
Total cost / ha (without drinking water) (£ ha^{1}) 
4.85 
Total cost / ha (with drinking water) (£ ha^{1}) 
8.71 
7.4. Catchment 4: The Esk
Table 36. Annual costs of soil erosion in the Esk catchment
Physical data 
Total Catchment area (ha) 
51,763 
Total areas at risk within catchment (ha) 
8,834 
Proportion at risk (%) 
0.17 
Soil depth loss (mm yr^{1}) 
0.20 
Catchment soil erosion (t yr^{1}) 
9,140 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.18 
Soil N loss (t yr^{1}) 
71 
Soil P loss (t yr^{1}) 
19 
Soil K loss (t yr^{1}) 
5 
Soil C loss (t yr^{1}) 
1,680 
Onsite costs 
Total catchment productivity loss due to erosion (£) 
11,196 
Catchment productivity loss due to erosion in risk area (£ ha^{1} ) 
1.27 
Total catchment productivity loss due to erosion in total area (£ ha^{1} ) 
0.22 
Total catchment N loss cost due to erosion (£) 
47,302 
Average catchment N loss cost due to erosion (£ ha^{1} risk area) 
5.35 
Average catchment N loss cost due to erosion (£ ha^{1} category area) 
0.91 
Total catchment P loss cost due to erosion (£) 
12,600 
Average catchment P loss cost due to erosion (£ ha^{1} risk area) 
1.43 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.24 
Total catchment K loss cost due to erosion (£) 
2,125 
Average catchment K loss cost due to erosion (£ ha^{1} risk area) 
0.24 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.04 
Total catchment C loss cost due to erosion (£) 
1,120 
Average catchment C loss cost due to erosion (£ ha^{1} risk area) 
0.13 
Average catchment C loss cost due to erosion (£ ha^{1} category area) 
0.02 
Offsite costs 
Cost of sediment removal in rivers & canals (£) 
47,069 
Cost of sediment removal in drinking water (£) 
164,511 
Cost of N in rivers and lakes (£) 
13,414 
Cost of N in transitional waters (£) 
706 
Cost of N in drinking water (£) 
14,332 
Cost of P in freshwater lakes (£) 
30,740 
GHG cost of soil C loss (£) 
83,831 
Total costs 
Total onsite cost 
74,343 
Total offsite cost (with drinking water costs) 
354,603 
Total offsite cost (without drinking water cost) 
175,760 
Total costs with drinking water costs 
428,946 
Total costs without drinking water 
250,103 
Total cost / ha (without drinking water) (£ ha^{1} ) 
4.83 
Total cost / ha (with drinking water) (£ ha^{1} ) 
8.29 
7.5. Catchment 5: The Tweed
Table 37. Annual costs of soil erosion in the Tweed catchment
Physical data 
Total Catchment area (ha) 
351,190 
Total areas at risk within catchment (ha) 
53,901 
Proportion at risk (%) 
15% 
Soil depth loss (mm yr^{1}) 
0.20 
Catchment soil erosion (t yr^{1}) 
66,220 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.19 
Soil N loss (t yr^{1}) 
525 
Soil P loss (t yr^{1}) 
160 
Soil K loss (t yr^{1}) 
35 
Soil C loss (t yr^{1}) 
10,258 
Onsite costs 
Total catchment productivity loss due to erosion (£) 
66,941 
Catchment productivity loss due to erosion in risk area (£ ha^{1} ) 
1.24 
Total catchment productivity loss due to erosion in total area (£ ha^{1} ) 
0.19 
Total catchment N loss cost due to erosion (£) 
351,722 
Average catchment N loss cost due to erosion (£ ha^{1} risk area) 
6.53 
Average catchment N loss cost due to erosion (£ ha^{1} category area) 
1.00 
Total catchment P loss cost due to erosion (£) 
108,668 
Average catchment P loss cost due to erosion (£ ha^{1} risk area) 
2.02 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.31 
Total catchment K loss cost due to erosion (£) 
15,684 
Average catchment K loss cost due to erosion (£ ha^{1} risk area) 
0.29 
Average catchment P loss cost due to erosion (£ ha^{1} category area) 
0.04 
Total catchment C loss cost due to erosion (£) 
6,839 
Average catchment C loss cost due to erosion (£ ha^{1} risk area) 
0.13 
Average catchment C loss cost due to erosion (£ ha^{1} category area) 
0.02 
Offsite costs 
Cost of sediment removal in rivers & canals (£) 
341,032 
Cost of sediment removal in drinking water (£) 
1,191,956 
Cost of N in rivers and lakes (£) 
99,742 
Cost of N in transitional waters (£) 
5,250 
Cost of N in drinking water (£) 
106,566 
Cost of P in freshwater lakes (£) 
265,117 
GHG cost of soil C loss (£) 
512,012 
Total costs 
Total onsite cost 
549,854 
Total offsite cost (with drinking water costs) 
2,521,675 
Total offsite cost (without drinking water cost) 
1,223,153 
Total costs with drinking water costs 
3,071,529 
Total costs without drinking water 
1,773,007 
Total cost / ha (without drinking water) (£ ha^{1} ) 
5.05 
Total cost / ha (with drinking water) (£ ha^{1} ) 
8.75 
7.6. Summary of catchment scale costs of soil erosion per annum
Tables 38  42 summarise the annual costs of soil erosion for each of the 5 case study catchments, by land use type, land use area and Erosion Risk Class. Areas occupied by each land use are given in Appendix 9.1 and in Tables 38  42. Table 43 gives an overview of all onsite and offsite costs (£) for all catchments. Table 44 gives the costs per hectare for each of the case study catchments. Finally, Table 45 gives the ranges of output values for all catchments.
Table 38. Summary of annual costs of soil erosion for the Ugie catchment (including drinking water treatment costs) L = Low, M = Moderate, H = High erosion risk class
Ugie 

Onsite and offsite costs (£ per annum) 
Total (£) 
% of total 
Land use 
Area (ha) 
Erosion Risk Class 
L 
M 
H 
Organomineral soils and peats 
Urban 
320 
 
 
 
 
 
 
Horticulture 
13 
27 
425 
 
77 
529 
0% 
Arable intensive 
177 
129 
3,285 
19 
579 
4,013 
1% 
Arable extensive 
12,122 
5,712 
101,754 
546 
56,952 
164,964 
49% 
Grassland improved 
11,583 
5,428 
115,582 
1,563 
27,337 
149,910 
44% 
Grassland unimproved 
5 
 
2 
5 
39 
46 
0% 
Rough grassland 
1,642 
82 
2,116 
36 
7,150 
9,384 
3% 
Forestry 
2,297 
62 
3,070 
61 
2,558 
5,752 
2% 
Woodland 
1,015 
54 
1,993 
39 
468 
2,554 
1% 
Wildscape 
705 
8 
153 
 
1,603 
1,764 
1% 
Total 
29,878 
11,501 
228,380 
2,270 
96,764 
338,915 
100% 
% of total 
100% 
3% 
67% 
1% 
29% 
100% 

Table 39. Summary of annual costs of soil erosion for the Pow catchment (including drinking water treatment costs)
L = Low,
M = Moderate,
H= High erosion risk class
Pow 

Onsite and offsite costs (£ per annum) 
Total (£) 
% of total 
Land use 
Area (ha) 
Erosion Risk Class 
L 
M 
H 
Organominerals soils and peats 
Urban 
80 
 
 
 
 
 
 
Horticulture 
 
 
 
 
 
 
0% 
Arable intensive 
48 
1 
953 
8 
499 
1,462 
4% 
Arable extensive 
2,268 
700 
18,909 
1,172 
3,878 
24,660 
64% 
Grassland improved 
811 
437 
7,672 
777 
290 
9,175 
24% 
Grassland unimproved 
 
 
 
 
 
 
0% 
Rough grassland 
82 
5 
229 
12 
23 
269 
1% 
Forestry 
715 
23 
1,678 
269 
253 
2,223 
6% 
Woodland 
293 
15 
528 
110 
142 
795 
2% 
Wildscape 
35 
0 
89 
 
3 
93 
0% 
Total 
4,332 
1,181 
30,059 
2,349 
5,088 
38,677 
100% 
% of total 
100% 
3% 
78% 
6% 
13% 
100% 

Table 40. Summary of annual costs of soil erosion for the Girvan catchment (including drinking water treatment costs)
L = Low,
M = Moderate,
H = High erosion risk class
Girvan 

Onsite and offsite costs (£ per annum) 
Total (£) 
% of total 
Land use 
Area (ha) 
Erosion Risk Class 
L 
M 
H 
Organomineral soils and peats 
Urban 
169 
 
 
 
 
 
 
Horticulture 
 
 
 
 
 
 
0% 
Arable intensive 
62 
92 
814 
 
 
907 
0% 
Arable extensive 
1,053 
384 
8,397 
805 
5,290 
14,876 
7% 
Grassland improved 
9,177 
2,240 
107,825 
19,148 
6,322 
135,536 
66% 
Grassland unimproved 
471 
 
517 
228 
3,463 
4,207 
2% 
Rough grassland 
3,964 
39 
8,033 
3,416 
11,116 
22,604 
11% 
Forestry 
6,438 
27 
7,483 
2,645 
9,332 
19,486 
10% 
Woodland 
1,537 
23 
3,315 
1,011 
401 
4,750 
2% 
Wildscape 
521 
2 
409 
48 
995 
1,454 
1% 
Total 
23,393 
2,808 
136,794 
27,300 
36,919 
203,821 
100% 
% of total 
100% 
1% 
67% 
13% 
18% 
100% 

Table 41 Summary of annual costs of soil erosion for the Esk catchment (including drinking water treatment costs)
L = Low,
M = Moderate,
H = High erosion risk class
Esk 

Onsite and offsite costs (£ per annum) 
Total (£) 
% of total 
Land use 
Area (ha) 
Erosion Risk Class 
L 
M 
H 
Organomineral soils and peats 
Urban 
358 
 
 
 
 
 
 
Horticulture 
16 
28 
397 
 
 
425 
0% 
Arable intensive 
923 
423 
16,669 
486 
609 
18,187 
4% 
Arable extensive 
11,635 
2,282 
106,438 
7,237 
17,835 
133,792 
31% 
Grassland improved 
6,485 
1,348 
64,198 
13,277 
15,415 
94,237 
22% 
Grassland unimproved 
302 
7 
495 
498 
1,451 
2,452 
1% 
Rough grassland 
23,191 
85 
12,388 
28,885 
113,130 
154,487 
36% 
Forestry 
5,920 
31 
7,312 
3,487 
6,807 
17,637 
4% 
Woodland 
2,559 
24 
3,543 
631 
2,531 
6,728 
2% 
Wildscape 
374 
2 
59 
285 
657 
1,002 
0% 
Total 
51,763 
4,229 
211,498 
54,785 
158,435 
428,946 
100% 
% of total 
100% 
1% 
49% 
13% 
37% 
100% 

Table 42 Summary of annual costs of soil erosion for the Tweed catchment (including drinking water treatment costs)
L = Low,
M = Moderate,
H = High erosion risk class
Tweed 
Onsite and offsite costs (£ per annum) 
Total (£) 
% of total 
Land use 
Area (ha) 
Erosion Risk Class 
L 
M 
H 
Organomineral soils and peats 
Urban 
2,376 
 
 
 
 
 
 
Horticulture 
1 
 
24 
 
 
24 
0% 
Arable intensive 
1,222 
852 
20,031 
451 
811 
22,146 
1% 
Arable extensive 
53,535 
24,455 
395,297 
19,526 
215,433 
654,710 
21% 
Grassland improved 
90,152 
18,896 
1,134,338 
141,200 
62,463 
1,356,897 
44% 
Grassland unimproved 
7,607 
254 
27,587 
20,567 
30,704 
79,112 
3% 
Rough grassland 
108,624 
858 
148,702 
134,886 
402,561 
687,008 
22% 
Forestry 
66,807 
1,053 
87,061 
43,008 
77,470 
208,592 
7% 
Woodland 
15,219 
509 
30,710 
10,296 
6,013 
47,528 
2% 
Wildscape 
5,648 
34 
2,473 
1,597 
11,410 
15,513 
1% 
Total 
351,190 
46,911 
1,846,223 
371,531 
806,865 
3,071,529 
100% 
% of total 
100% 
2% 
60% 
12% 
26% 
100% 

Table 43. Summary of onsite and offsite annual costs (£) for all catchments.
L = Low,
M = Moderate,
H = High erosion risk class
Catchment 
Area of catchment (ha) 
Onsite (£) 
Offsite (without drinking water) (£) 
Offsite (with drinking water) (£) 
Total (without drinking water) (£) 
Total (with drinking water) (£) 
1. Ugie 
29,878 
60,281 
134,580 
278,634 
194,861 
338,915 
2. Pow 
4,332 
5,724 
13,761 
32,953 
19,485 
38,677 
3. Girvan 
23,393 
34,939 
78,421 
168,882 
113,360 
203,821 
4. Esk 
51,763 
74,343 
175,760 
354,603 
250,103 
428,946 
5. Tweed 
351,190 
549,854 
1,223,153 
2,521,675 
1,773,007 
3,071,529 
Table 44. Summary of annual costs /
ha (£
ha^{1})
Catchment 
Cost / ha (without drinking water) (£ ha^{1} ) 
Cost / ha (with drinking water) (£ ha^{1} ) 
1. Ugie 
6.52 
11.34 
2. Pow 
4.50 
8.93 
3. Girvan 
4.85 
8.71 
4. Esk 
4.83 
8.29 
5. Tweed 
5.05 
8.75 
Table 45. Ranges of annual values for the 5 study area catchments
Total catchment areas (ha) 
4,332  351,190 
Total areas at risk within catchments (ha) 
511  53,901 
Proportion at risk (%) 
12%  17% 
Soil depth loss (mm yr^{1}) 
0.20  0.29 
Catchment soil erosion (t yr^{1}) 
1,016  66,220 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.18  0.25 
Soil N loss (t yr^{1}) 
5  525 
Soil P loss (t yr^{1}) 
2  160 
Soil K loss (t yr^{1}) 
0.34  35 
Soil C loss (t yr^{1}) 
81  10,258 
On site costs £ 
5,724  549,854 
Off site costs (without drinking water) £ 
13,761  1,223,153 
Off site costs (with drinking water) £ 
32,953  2,521,675 
Total Costs (without drinking water) £ 
19,485  1,773,007 
Total Costs (with drinking water) £ 
38,677  3,071,529 
Cost / ha £ ha^{1} (without drinking water) 
4.50  6.52 
Cost / ha £ ha^{1} (with drinking water) 
8.29  11.34 
7.7. The national scale
Glenk et al. (2010) tried to estimate the total costs of soil erosion at the national scale, but concluded that a more case study specific approach was needed first (hence this project). The methodology has been applied successfully to the 5 case study catchments. The same approach was then applied at the national scale, running the economic model with national estimates of land use (to determine soil erosion rate) and Soil Erosion Risk Classes (to determine erosion probability).
A summary of the physical results, and the onsite and offsite costs per annum are shown in Table 46.
Table 46. Total annual costs of soil erosion in Scotland
Physical data 
Total area (ha) 
7,108,057 
Total areas at risk within catchment (ha) 
1,271,735 
Proportion at risk (%) 
18% 
Soil depth loss (mm yr^{1}) 
0.23 
Catchment soil erosion (t yr^{1}) 
918,971 
Average catchment soil erosion (t ha^{1} yr^{1}) 
0.13 
Soil N loss (t yr^{1}) 
9,778 
Soil P loss (t yr^{1}) 
2,235 
Soil K loss (t yr^{1}) 
520 
Soil C loss (t yr^{1}) 
218,000 
Onsite costs 
Total Scotland productivity loss due to erosion (£) 
1,244,832 
Scotland productivity loss due to erosion in risk area (£ ha^{1}) 
1.0 
Total Scotland productivity loss due to erosion in total area (£ ha^{1} ) 
0.2 
Total Scotland N loss cost due to erosion (£) 
6,550,928.0 
Average Scotland N loss cost due to erosion (£ ha^{1} risk area) 
5.2 
Average Scotland N loss cost due to erosion (£ ha^{1} category area) 
0.9 
Total Scotland P loss cost due to erosion (£) 
1,519,862 
Average Scotland P loss cost due to erosion (£ ha^{1} risk area) 
1.20 
Average Scotland P loss cost due to erosion (£ ha^{1} category area) 
0.21 
Total Scotland K loss cost due to erosion (£) 
234,178 
Average Scotland K loss cost due to erosion (£ ha^{1} risk area) 
0.18 
Average Scotland P loss cost due to erosion (£ ha^{1} category area) 
0.03 
Total Scotland C loss cost due to erosion (£) 
145,333 
Average Scotland C loss cost due to erosion (£ ha^{1} risk area) 
0.11 
Average Scotland C loss cost due to erosion (£ ha^{1} category area) 
0.02 
Offsite costs 
Cost of sediment removal in rivers & canals (£) 
4,732,699 
Cost of sediment removal in drinking water (£) 
16,541,473 
Cost of N in rivers and lakes (£) 
1,857,726 
Cost of N in transitional waters (£) 
97,775 
Cost of N in drinking water (£) 
1,984,833 
Cost of P in freshwater lakes (£) 
3,708,016 
GHG cost of soil C loss (£) 
10,880,806 
Total costs 
Total onsite cost 
9,695,133 
Total offsite cost (with drinking water costs) 
39,803,328 
Total offsite cost (without drinking water cost) 
21,277,022 
Total costs with drinking water costs 
49,498,461 
Total costs without drinking water 
30,972,155 
Total cost / ha (without drinking water) (£ ha^{1} ) 
4.36 
Total cost / ha (with drinking water) (£ ha^{1} ) 
6.96 