Slipper Mill Pond Preservation Association
Registered Charity No:277744

River Ems - Notes

These notes cover the features of the lower reaches of the river affecting the pond. In practice this means the section South of the A27-Emsworth Bypass

A27 Embankment (SU 4753 1066)

The River Ems crosses the embankment in two places - in a culvert and via a syphon.

A constantly running spring found during the A27 construction has been piped and surfaces just south of the railway at SU 4750 1063.

Constant Springs and Lumley Mill (SU 4752 1064)

Groundwater levels in this area are always high.

The Westernmost branch of the Ems is piped (see A27 Embankment), and joins the Western arm of the Lower Ems beyond the railway line. The main river flows directly to Lumley Mill whilst the Eastern branch runs to the West of Mill Lane and then to Lumley Mill.  There is a side branch/overflow which is shown on OS maps to connect to the Hermitage Brook.

Constant Springs Sluice in spate - March 2001

The main streams combine at the sluice just below Lumley Mill and then split into two. The spillway channel to the east is controlled by a sluice fitted by the owner of Constant Springs and runs down past the cottages in Lumley Road to Peter Pond. The western channel is controlled by stop boards and a weir and continues south under the railway. A minor side channel from this feeds some water features.

The flow in each of the channels is interlinked and controlled by a number of sluices.  In winter these channels run full to capacity and it is usual for the garden of Constant Springs to be waterlogged. Constant Springs house has cellars which are below normal groundwater levels and often has flooding problems. The groundwater level is said to be never more than 0.5m. below ground level even in summer.  The area between the house and the A27 is regularly flooded in winter.

Western Branch of the Ems (SU 4750 1062)

After leaving Constant Springs the main channel turns sharply westward immediately south of the railway line. The Westernmost branch culvert joins the channel where it turns South again. This branch of the river also takes runoff from the A27.

Culvert joins main channel	Westward turn of main channel	Main channel - under railway

The river proceeds southwards until SU 4750 1060 where there is a weir into a bunded area to the West of Gooseberry Cottage. This was constructed by the DoT, when the A27 was upgraded, as a balancing pond area. There is a non return valve at the southern end where it exits into Peter Pond. This bunded area is waterlogged during the winter months.

Gooseberry Cottage is lower than Peter Pond and used to flood fairly frequently - bunds have now been constructed in an attempt to prevent this.

The main channel continues southwards along the western edge of the bunded area ( where the pond for the Old Flour Mill used to be) until it passes under the A259 at SU 4751 1051. After a few metres, the channel widens and divides into two. One channel (the spillway) turns eastwards via a sluice. The other channel proceeds south towards Queen Street Mill.

Queen Street Mill (SU 4752 1057)

Debris grating and entrance to Mill

The Mill has been converted into offices. There is a turbine, still in place under the mill which is now prevented from turning and bypassed because of the noise it produces when working. It is alleged that this does not restrict flows under the mill. It has been suggested that the turbine could be removed as it is of industrial archaeological interest but the suggestion was rejected by the owner on the grounds that the channel under the mill is in poor condition.

The discharge from the mill is into the sea at Dolphin Quay and is O.75m high and 1.75m. wide.

A secondary spillway runs parallel to the A259 for part of the way. A culvert 0.5m high and 1.5m wide has been constructed and it emerges at SU 47552 1057.

Eastern Branch - Cottages in Lumley Lane SU 4751 1062

Lumley cottages and gardens

The gardens of these cottages are flooded under exceptional circumstances. The upper tidal limit is shown on OS maps at about the middle cottage. This has been observed at exceptional tide and weather conditions. Problems have been experienced with vegetation obstructing the channel and causing flooding when the channel has had to cope with large flows.

Eastern Branch - Peter Pond (SU 4752 1059)

This is hydraulically continuous with Slipper Mill Pond. Hermitage Brook enters from the East side via a non-return valve and takes the discharge from the Hermitage Housing SUDS system. Brook Cottage, flanking the brook, and the adjacent stretch of Lumley Road are the lowest lying points in the area apart from Gooseberry Cottage.

Gooseberry Cottage	A259 Bridge and connection to Slipper Mill Pond	Hermitage Brook as seen from Lumley Road

Eastern Branch - Slipper Mill Pond (SU 4753 1056)

South Wall Sluice and Gates

Tidal flap gates at the seaward end allow seawater to enter when the tide is high enough. The adjacent sluice is used to lower the pond level for bank maintenance. Levels in the pond are maintained to preserve wildlife both in the Slipper and Peter ponds..

The general bank crest level is lower that the lowest point of Lumley Road. Tidal flooding of the road and elsewhere can only occur when the bank is submerged and is independent of the management regime of the gates and sluice. The A259 between Slipper Pond and Peter Pond is also affected by tidal flooding under extreme conditions.

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