Test and Itchen catchment
• Swaythling • Hampshire • ID: E12412 • Level
(1h ago) • 2 readings/hr • 172 views
Set water level alerts
Get notified about Riverside Park — tick as many as you like, they all share the notify settings below.
1 person already gets alerts for this gauge.
Alert me when (tick one or more)
⤴Unusual rise — FloodRadar+Top 1% rise rate for this gauge.
Height for "Above a height"
Drag the line on the chart, or type a value:mASD
Quick pick:
You'll be notified when this gauge is rising more than 0.10 m/hr — a sign of rapidly increasing water levels.
You'll be notified when a new storm-overflow (sewage) discharge starts within ~3 km of this gauge, based on the water companies' near-real-time feeds.
Notify by (tick one or more)
Your browser will ask permission, then you'll get a notification even when FloodRadar isn't open.
On iPhone: tap Share → Add to Home Screen first, then open it from there and set the alert. Show me how
Each one is saved as its own alert — pause or remove them individually any time.
Not an emergency service — if in danger call 999. Alerts rely on
EA/SEPA/NRW data and are best-efforts. Terms
Last Level
1.318 mASD
⚠ 1h ago · may be out of date
24h Max
1.360 mASD
24h Min
1.299 mASD
Typical Range
1.40 - 2.05
mASD
Highest Recorded
2.19 mASD
EA official record
A 2.75 reading (4 Jan 2014) sits in our unverified raw history and is not treated as the record
Current level is 60% of this
🚽Sewage overflows nearby
Recent Water Levels
🌍 floodradar.co.uk
1 day
EA forecast (official)
Prediction V2
Prediction Eris
Nimbus beta
Experimental model fusing soil moisture, river flow, groundwater and catchment
character. The shaded band is its 10–90% range, widened so that about 80% of recent outcomes fall inside it.
Under evaluation — not yet promoted, so treat as a second opinion.
River Flow
90 days
Daily mean discharge (m³/s) with the daily min–max band, from the EA Hydrology API. Flow is the volume of water passing the gauge — often a more direct flood signal than level.
RIVERSIDE PARK GS (E12411) — flow at this site
7 days
A separate gauge 5.1 m from this one at the same site, shown here for context.
Its readings are its own and are never merged with this page's.
Flow Data: Daily mean flow (m³/s) to 7 Oct (2 days behind — the EA publishes each day's mean a day or two after it ends; unchecked, provisional)via EA Hydrology
Storm overflows whose water reaches this gauge on the mapped river network, nearest first by distance along the river. The status is each water company's monitor: it says whether an overflow is discharging, not how much or what it contains.
3 storm overflows are traced upstream of this gauge, the nearest 970 m away along the river. 0 report discharging now, 3 report not discharging.
Southern Water · into River Itchen · 2.3 km away in a straight line · discharges into a tidal reach, where the water moves both ways
0 spills · 0 hours in 2025
Status unknown — the live feed has not updated for 9 d 12 h
15 more within 6 km whose connection is not known.
2 other overflows within 6 km are downstream of this gauge or on another branch of the river network, so they are not listed.
These are the water companies' monitor statuses; a spill does not by itself explain a change in the gauge level. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels. Explore the sewage map →
Warnings apply to a whole flood area, not necessarily this exact spot. Years before 2006 aren't covered by the EA's historic record.
See also the Swaythling flood history.
Flood areas linked to this gauge
Flood warnings and alerts are issued for whole areas. These are the 8 areas linked to this gauge, nearest first.
🌊 Groundwater-fedSlow and steady — fed largely by groundwater, so levels change gradually, not in sudden spikes.
Your catchment is all the land that drains rainfall into the river above this gauge. Its character — how
steep, wet, wooded, urban or chalky that land is — decides how fast rain here turns into a rising river. A steep, bare or clay
catchment is “flashy” (rises and falls quickly, floods easily); a flat, chalk or well-wooded one is
slow and steady. The tiles below put numbers to that; the flow-duration curve reads left-to-right
from the river’s typical high flows (Q5) down to its low flows (Q95) — a steep curve means a flashy river.
The physical character of the land that drains to this gauge, and how it shapes its flood response — from the National River Flow Archive (UKCEH).
Baseflow Index
0.89
groundwater-fed — slow & steady
Avg Annual Rainfall
910 mm/yr
1991–2020 · +5% since 1941–70
Urban Extent
4.5%
partly urbanised
Highest Daily Mean Flow
27.25 m³/s
28 Mar 2024 · daily mean, not the instantaneous peak
Flow-Duration Curve
Daily flow (m³/s) exceeded each % of the time — a steep curve is flashy, a flat one is steady. Q5 high · Q50 median · Q95 low.
Land Cover (2023)
Woodland 11%Grassland 31%Arable 48%Urban 10%
Flow affected by: reservoir influence, public water supply, effluent returns.
Photos
Gauging-station photographs from the National River Flow Archive (UKCEH).
Ultrasonic gauging station (multi-path with reflector).
More detail
The catchment
Principally a rural, Chalk catchment but with appreciable urban growth near the outfall (where impervious Tertiary formations predominate).
The station
Ultrasonic gauging station (multi-path with reflector). Gauge replaced in 2008 and data produced are now good.
How it measures flow
Problems in period of record data caused by clogging of ultrasonics by weed growth; Tidal effects occasionally evident (dependant on downstream sluice operation).
Flow regime
Flows artificially influenced by two 45 megalitres/day surface water abstractions at Gaters Mill and Otterbourne and a large sewage treatment works discharge at Eastleigh. Groundwater augmentation (in headwaters) can be important.
How this gauging station is built and how long it has measured (NRFA / UKCEH).
Gauge type
Ultrasonic
Operating since
1981
Station datum
0.7 mAOD
Flow record
1982–2024 · 42 yrs · 99% complete
Hydrometric area
42
Measured by
Environment Agency
Nearby Groundwater
Soil Moisture
Possible storm-overflow correlation
Frequently asked questions
Is the River Itchen at Riverside Park flooding today?
The current level is 1.32m, which is below the typical range. Flooding is very unlikely at this level.
Is the river level rising or falling at Riverside Park?
Based on the most recent readings, the level is currently falling slightly. The chart above shows the last 12 hours of measurements by default (up to 7 days), updated roughly every 15 minutes.
Why is the level slowly falling?
When little or no rain has fallen for a while, a river level gradually drops as the water stored in the ground and soil drains away with nothing to replace it. This is called baseflow recession and is normal in dry spells. Only about 0.0mm of rain has fallen nearby in the last 7 days, so the flow is being sustained mainly by groundwater. A gentle decline like this is expected and is not a sign of a problem — downstream gauges often recede a little faster than headwaters further upstream, and levels recover once rain returns.
What is a normal level for the River Itchen at Riverside Park?
The typical range at this station is 1.40m to 2.05m, based on Environment Agency historical data. Levels above 2.05m are higher than usually seen and may indicate a flood risk.
How often is this river level data updated?
Readings are supplied by the Environment Agency gauge. FloodRadar checks for updates roughly every 15 minutes; the timestamp above shows how recent the latest available reading is.
Embed this gauge on your website
Free live river-level widget — ideal for parish councils, angling clubs and local sites. Updates automatically.
Preview
📮 Flood risk by postcode near this gauge
Postcodes within 5 km with properties in the Environment Agency’s rivers-and-sea flood-risk bands:
FloodRadar
Log inCreate free account
