Dataset

Hogsmill Water Quality

Dataset summary

Observations

10 January 2026

Downstream Stepping Stones

19 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, oxygen, ph, phosphate, water depth, water flow, water level, water temperature

10 January 2026

Green Lanes A (downstream of old green lanes stream)

20 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, oxygen, ph, phosphate, water depth, water flow, water level, water temperature

9 January 2026

Ewell Storm Tank

14 parameters tested

air temperature, alkalinity, ammonia, chlorine, conductivity, hardness, nitrate-nitrogen, oxygen, ph, phosphate, weather in the past 24hrs, water depth, water flow, water temperature

8 January 2026

Berrylands Bridge

27 parameters tested

air temperature, algae, alkalinity, ammonia, chloride, chlorine, clarity, colour, conductivity, current weather, current weather description, hardness, nitrate-nitrogen, nitrites, odour, water surface, oxygen, ph, phosphate, pollution sources, weather in the past 24hrs, weather in the past 24hrs description, water depth, water flow, water level, water temperature, water use

24 December 2025

Bonegate Stream

23 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrites, odour, water surface, oxygen, ph, phosphate, pollution sources, weather in the past 24hrs, water depth, water flow, water level, water temperature, water use

13 December 2025

Downstream Stepping Stones

19 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, oxygen, ph, phosphate, water depth, water flow, water level, water temperature

13 December 2025

Green Lanes A (downstream of old green lanes stream)

20 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, oxygen, ph, phosphate, water depth, water flow, water level, water temperature

12 December 2025

Ewell Storm Tank

15 parameters tested

air temperature, alkalinity, ammonia, chlorine, conductivity, current weather, hardness, nitrate-nitrogen, oxygen, ph, phosphate, water depth, water flow, water level, water temperature

11 December 2025

Berrylands Bridge

26 parameters tested

air temperature, algae, alkalinity, ammonia, chloride, chlorine, clarity, colour, conductivity, current weather, current weather description, hardness, nitrate-nitrogen, nitrites, odour, water surface, oxygen, ph, phosphate, pollution sources, weather in the past 24hrs description, water depth, water flow, water level, water temperature, water use

5 December 2025

Bonesgate

23 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, current weather description, hardness, odour, water surface, oxygen, ph, phosphate, pollution sources, weather in the past 24hrs, weather in the past 24hrs description, secchi depth (clarity), water flow, water level, water temperature

4 December 2025

Middle Mill

19 parameters tested

air temperature, algae, alkalinity, ammonia, chloride, clarity, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, ph, phosphate, weather in the past 24hrs, water flow, water level, water temperature

18 November 2025

Saipem S5 - Tolworth Brook

21 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrites, odour, water surface, ph, phosphate, weather in the past 24hrs, secchi depth (clarity), water depth, water flow, water level, water temperature

10 November 2025

Bonegate Stream

23 parameters tested

air temperature, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, oxygen, ph, phosphate, weather in the past 24hrs, weather in the past 24hrs description, secchi depth (clarity), water depth, water flow, water level, water temperature, water use

8 November 2025

Downstream Stepping Stones

21 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, oxygen, ph, phosphate, weather in the past 24hrs, water depth, water flow, water level, water temperature

8 November 2025

Green Lanes A (downstream of old green lanes stream)

13 parameters tested

air temperature, alkalinity, ammonia, chlorine, conductivity, current weather, hardness, nitrate-nitrogen, oxygen, ph, phosphate, water depth, water temperature

7 November 2025

Bonesgate

16 parameters tested

air temperature, alkalinity, ammonia, chlorine, colour, conductivity, hardness, nitrate, odour, oxygen, ph, phosphate, pollution sources, weather in the past 24hrs, water level, water temperature

6 November 2025

Ewell Storm Tank

13 parameters tested

air temperature, alkalinity, ammonia, chlorine, conductivity, current weather, hardness, nitrate-nitrogen, oxygen, ph, phosphate, water depth, water temperature

6 November 2025

Berrylands Bridge

26 parameters tested

air temperature, algae, alkalinity, ammonia, chloride, chlorine, clarity, colour, conductivity, current weather, current weather description, hardness, nitrate-nitrogen, nitrites, odour, water surface, oxygen, ph, phosphate, weather in the past 24hrs, weather in the past 24hrs description, water depth, water flow, water level, water temperature, water use

3 November 2025

Saipem S2- Middle Mill

13 parameters tested

air temperature, alkalinity, ammonia, chlorine, conductivity, current weather, hardness, nitrate, ph, phosphate, weather in the past 24hrs, water depth, water temperature

28 October 2025

Middle Mill

20 parameters tested

air temperature, algae, alkalinity, ammonia, chlorine, clarity, colour, conductivity, current weather, hardness, nitrate-nitrogen, odour, water surface, ph, phosphate, weather in the past 24hrs, weather in the past 24hrs description, water flow, water level, water temperature