What is being monitored?

A whole range of measurements are being taken to record changes in surface water and groundwater quality. The Wensum Alliance has helped identify monitoring needs and locations for monitoring equipment. Key features of the monitoring programme are shown below:

Surface Water Monitoring

Three spatial scales:

  • Wider catchment (existing monitoring sites)
  • Sub-catchment scale (<10 km2) (investigation of source-transport pathways)
  • Mini-catchment scale (<1 km2) (investigation of mitigation measures)

Dual-instrumentation approach using:

  • Sensor web-based monitoring technology
  • Autoanalysers + conventional autosamplers + multi-parameter sonde + weather station + stream flow gauging

Key measurements:

  • DO, temp, EC, pH, Cl, redox potential
  • Turbidity, suspended solids concentration
  • Chlorophyll
  • Total P, PO4
  • Total N, NO3, NO2, NH4
  • Faecal indicator organisms, BOD, DOC

Biological monitoring:

  • Annual/seasonal monitoring using standardised equipment in accordance with monitoring protocols
  • Expansion of current Catchment Sensitive Farming monitoring (invertebrates, fish, diatoms, macrophytes)
  • Ecological status expressed using Biological Monitoring Working Party (BMWP) biotic scoring method for bottom-dwelling (benthic) invertebrates
  • BOD data, biotic scores and abundance of aquatic insects to assess biological status and the impact of oxygen depletion caused by diffuse pollution inputs
  • Replicate biotic scores from manipulated and control catchments with analysis by ANOVA or equivalent non-parametric tests for non-normally distributed data

Groundwater monitoring:

  • Paired shallow (Quaternary deposits) and deep (Chalk) boreholes for groundwater level and quality monitoring in the manipulated mini-catchments to monitor catchment responses to recharge events.
  • New borehole installations to core the unsaturated zone to provide solute profiles.