EA Groundwater Levels MCP Server

EA Groundwater Levels

The Environment Agency Hydrology API provides groundwater level monitoring data from borehole stations across England. Data is measured as metres above ordnance datum (mAOD).

Data Model

• Stations — Groundwater monitoring boreholes with location, aquifer name, borehole depth, and date opened. Filtered by observedProperty=groundwaterLevel to get only groundwater stations.
• Measures — Individual measurement series from a station. Groundwater measures have parameter "level" and may be "logged" (automatic, sub-daily) or "dipped" (manual, infrequent).
• Readings — Time-series values from measures with date, value (mAOD), and quality flag.

Key Patterns

• Station IDs are long compound strings: {stationGuid}_{wiskiID} (e.g. c7e13884-4a02-4df3-b184-09aea28cf8e8_3_020).
• Measure IDs include the station ID plus type info (e.g. ..._3_020-gw-logged-i-subdaily-mAOD-qualified).
• Use observedProperty=groundwaterLevel to filter stations to groundwater only.
• Geo-filter with lat, long, dist (km radius) on station list endpoint.
• Readings are fetched via the measure ID, not the station ID directly.

Gotchas

• No auth: Completely open API under OGL v3.
• No _sorted param on readings: The readings endpoint does not support _sorted. Data comes in chronological order.
• Station IDs have underscores: The notation field is the station ID and contains underscores.
• Logged vs dipped: Logged measures are automatic (every 15 min to 1 hour). Dipped measures are manual field visits (monthly or less).
• Historical data: Some stations have data going back to the 1970s. Use since or date to limit.