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Pesticide Model – Full Details

Top Pesticides Top Pesticides Runs for Surface Water Catchments and for Ground Water boreholes:

Data export option to Excel:

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SWAT Model SWAT Model -- Top PesticidesTop Pesticides

Catchment based threshold exceedenceCatchment based threshold exceedenceUses either Seasonal exposure or Pesticide specific loadings :

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SWATCATCH ModelSWATCATCH Model

Catchment based threshold exceedence

Groundwater assessment for all Groundwater assessment for all boreholesboreholes

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Groundwater assessment for a Groundwater assessment for a single boreholesingle borehole

Identify Catchment HotIdentify Catchment Hot--Spots:Spots:Ground Water:

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GWAT ModelGWAT Model

Soil, pesticide, climate datag/w resources identified from EA g/wvulnerability mapping and SPZs

Soil leaching model (MACRO)

Attenuation factor model (unsat zone)

‘local’ g/wUsing id for likely g/wresources

aquifersUsing id EA major/minor aquifers

boreholesGrids in SPZ

Identify Catchment HotIdentify Catchment Hot--SpotsSpotsSurface Water:

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SWAT Model SWAT Model -- Catchment HotCatchment Hot--spotsspots

Bespoke Reporting OutputBespoke Reporting Output

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Current Developments

Nitrates, Climate Change, Leakage and AMP

Current Developments Current Developments -- NitratesNitratesSurface water Nitrate model

Calculates the agriculturally-derived nitrate concentrations at the surface water abstraction point based on the amount of leachable N available for transport over the whole sub catchment area that feeds the surface water source

Integrates land use, soil and climate zone data over the sub catchment

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Surface water Nitrate model - Output

Yearly Spread - Nitrate for Upper Severn

0

5000

10000

15000

20000

25000

30000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Year

Flow

(ml/d

ay)

0

5

10

15

20

25

30

35

Nitr

ate

NO

3 C

once

ntra

tion

(mg/

l)

Mean flows (ml/day) Base flows (ml/day) Nitrate NO3 conc (mg/l)

Current Developments Current Developments -- NitratesNitrates

Groundwater Nitrate modelV = volumeN = NitrateStore starts with no nitrate or volume

Instant input from model

N1V1

STEP 1GW Store N1V1 in store N0V0 Output to baseflow

at step end

Becomes Instant input from modelStep 2 startV and N

N2V2

STEP 2GW Store N2V2 in store N1V1 Output to baseflow

at step end

Becomes Instant input from modelStep 3 startV and N

N3V3

STEP 3GW Store N3V3 in store N2V2 Output to baseflow

at step end

Current Developments Current Developments -- NitratesNitrates

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Groundwater Nitrate model - Output

Current Developments Current Developments -- NitratesNitrates

Yearly Spread - Nitrate for 1km around AMEN CORNERWeather Data = Current

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Year

Flow

(m³/w

eek)

0

5

10

15

20

25

Con

cent

ratio

n (m

g/l)

storage (m³/week) vol to gwater store (m³/week) Nitrate N conc in recharge(mg/l) Nitrate N conc in gwater store (mg/l)

Current Developments Current Developments –– Climate ChangeClimate Change

CurrentData

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Derivation of Scenario Weather DataDerivation of Scenario Weather DataUKCIP02 climate change scenario data Monthly precipitation and temperature for 30 year timeslice (e.g. 2020’s =2011-2030)

Derivation of weekly HERDistributed corresponding to current patterns within each month

Calculation of simple water balance modelPrecipitation – potential evapotranspiration balance to derive monthly HER. Problems with PET calculation from temperature

Scenario HERWeather time-series for each10 weather stations snapped into CatchIS module

Impact on Pesticide RiskImpact on Pesticide Risk

Yearly Spread - Isoproturon on Wheat for Maun to Conjure AldersWeather Data = Current

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Year

Flow

(m³/S

)

0

20

40

60

80

100

120

140

160

Con

cent

ratio

n (n

g/l)

Mean flows (m³/S) Base flows (m³/S) Mean Pesticide conc (ng/l) Peak Pesticide conc (ng/l)

Yearly Spread - Isoproturon on Wheat for Maun to Conjure AldersWeather Data = 2020 - Low Distributed

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Year

Flow

(m³/S

)

0

20

40

60

80

100

120

140

160

Con

cent

ratio

n (n

g/l)

Mean flows (m³/S) Base flows (m³/S) Mean Pesticide conc (ng/l) Peak Pesticide conc (ng/l)

• Lower mean flows • Smoothing extreme events• Likelihood of threshold exceedence slightly increased

Maun to Alders sub-catchmentIsoproturon on wheat

CURRENT 2020 LO

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Current Developments Current Developments ––Leakage and Asset ManagementLeakage and Asset Management

Pipe failure (Corrosivity, Sharps, Sand and Heave)

Leakage and Asset ManagementLeakage and Asset Management

Leakage management is an important element in the supply-demand balance and AMP for water supply companies.

Progressively leakage has become a political issue and OFWAT has imposed annual mandatory targets for all water companies.

Leakage reduction is important in the management of water supplies and its contribution to the sustainable management of water resources.

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CIWEMCIWEM’’ss positionposition

CIWEM recognises the considerable reductions in leakage made by water companies in recent years.

CIWEM recommends that a Best Available Technique not Entailing Excessive Cost (BATNEEC) type approach be considered for leakagetarget setting within an economic framework.

CIWEM recommends that the ownership of supply pipes be transferred to the water companies.

CIWEM recommends that in the long term, all water use should be metered for the purposes of water conservation and more accurateleakage measurement.

CIWEM supports an holistic approach to leakage control, by considering the components of leakage and selection of appropriate policies.

Causes of leakageCauses of leakage

Failure in the water mains network

How?

Age of pipe

Diameter of pipe

Source of feed

‘Bus’ loading

Soil Heave potential

Soil Corrosivity potential

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How soils affect leakageHow soils affect leakage

Lower corrosivity Higher corrosivity

Less heave More heave

How soils affect leakageHow soils affect leakage

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Potential areas of developmentPotential areas of development

Erosion risk

Cryptosporidia risk