Catchment

Type

Area

(m²)

Weighted

Area

(%)

Average Coefficient

of Runoff

Estimated Total N

(mg/L)

Weighted Total N

(mg/L)

Estimated

Total

Phosphate

(mg/L)

Weighted Total

Phosphate (mg/L)

Buildings

5600

6.8

0.95

0

0

0

0

Roads

3900

4.8

0.85

0

0

0

0

Grass

8164

20

0.25

27.4

1.37

0.5

0.02

Trees

9471

17.2

0.20

11.6

0.40

0.9

0.03

Seasonally Irrigated Soil

21,851

21.2

0.10

20.2

0.43

0.3

0.01

Not irrigated Soil (other amenities)

32,657

30

0.10

7.8

0.23

0.5

0.015

Total

81,643

100%

-

-

2.43

-

0.08