10A: LANGSTONE AND CHICHESTER HARBOURS The Kench saltmarsh - HCC Countryside Service Site near entrance to Langstone harbour -with house boats backdrop of Portsmouth and Portsdown Hill. Entrance to Langstone harbour – Mill Rythe – North creek tidal inlets Racing in Langstone – backdrop of Eastney pumping station background which almost completely dry out at Fort Widley low water. Hayling Bridge - Wadeway in Fowley Island – remnant Oyster bed Mulberry harbour Hayling ferry, relic foreground. Algal summer bloom – Chichester harbour WW2 Mulberry mid distance and over mud flats. Portsdown Hill backdrop Hampshire County 1 Status: FINAL May 2012 Integrated Character Assessment Langstone and Chichester Harbours Hampshire County 2 Status: FINAL May 2012 Integrated Character Assessment Langstone and Chichester Harbours 1.0 Location and Boundaries 1.1 This character area is located in the far southeast of the County adjoining West Sussex. It is defined by the mean high water mark of the harbours and includes the harbour mouths. 1.2 Component County Landscape Types Intertidal Harbour 1.3 Composition of Borough/District LCAs: Havant Borough Langstone Harbour Chichester Harbour This LCA includes the harbour mouths and is different to the Borough character area boundaries in this regard. The harbour mouths are seen as part of the harbour seascape rather than the coastal sea particularly in terms of recognised ‘management areas ’ i.e. the Chichester Harbour AONB boundary and Langstone Harbour Board boundary. The AONB character areas are also closely aligned with the Borough ones. 1.4 Associations with NCAs, Natural Areas and England’s Historic Seascapes NCA: None Marine NA 109: Solent and Poole Bay, Solent and Waters off the Isle of Wight: Langstone Harbour and Chichester Harbour. 2.0 Key Characteristics • A shallow marine basin enclosed by a low lying natural and man made sea defence shoreline of low walls and embankments. • A varied underlying geology of clays and sands and chalk overlaid with beach, tidal flat deposits with some raised marine deposits predominantly of thick gloopy, anaerobic mud. • A hugely fluctuation seascape from almost completely covered at high water to about 90% exposed muds, shingle and sand at low water. • Small islands and areas of saltmarsh in upper reaches of the harbours which dissipate wave action on the shore. • A nationally renowned recreational sailing area, with a much reduced commercial shipping use, although fishing and in particular oyster and clam fishing is important to the local economy. • Within the harbours there is strong sense of remoteness and separation from the surrounding highly populated areas. • A skyline of contrasts from the city skyline of Portsmouth to the hills of Portsdown, South Downs chalk ridge and profile of the Isle of Wight. Hampshire County 3 Status: FINAL May 2012 Integrated Character Assessment Langstone and Chichester Harbours • Rare and internationally important coastal habitats with many layers of designation. • Remains of well preserved archaeological sites in intertidal areas including prehistoric forest, peat deposits, stone tools, Bronze Age settlement and burial remains, Roman pottery and salt workings, Saxon watercraft and fishing related structures and a few modern ship wrecks. • A coastline which been subject to much change and realignment due to reclamation, natural processes and hardening. 3.0 Physical Characteristics and Uses 3.1 The underlying geology comprises sedimentary rocks, with older White chalk in the northern part of the character area and Tertiary deposits of London clay and Reading beds in the south. The different geological members have been flexed into a series of eastwest folds which have been eroded to produce a narrow sequence of geological bands. 3.2 Langstone and Chichester harbours are shallow marine basins characterised predominantly by mud flats but also sand banks particularly in the southern reaches and raised marine beach deposits of shingle particularly on lee shores. There are two small sand shingle spits which project into the harbours on either end of Hayling. The Langstone harbour shoreline is less indented by small creeks and rithes than the east side of Hayling. Much of the coastline has sea defences in varying degrees of condition which have gradually restricted the area of the upper parts of the littoral zone, squeezing this habitat. The main channels include Emsworth, Sweare Deep in Chichester and, Broad Lake, North and South Lake and Broom channel in Langstone. The channels are not particularly deep but at the harbour mouths are up to 13m at Mean Low Water Springs (MLWS). Mineral dredging has taken place in the harbour mouths and elsewhere to maintain navigation such as New Cut at Northney which was on the Portsmouth to Arundel canal. An area at Sinah sands is licensed for gravel extraction but not currently worked due to the environmental sensitivity of the area. 3.3 The wide tidal range, coupled with the shallow gradient of the mud flats, produces contrasting environments at high and low water. At MLWS, between 15% and 20% of the character area is covered by water compared with close to 95% at MLWS. The short fetch and shallow waters leads to a short ‘chop’ small high frequency waves in the stronger winds of a predominant south westerly especially against the tide. The Chichester harbour side is noticeably flatter in these conditions. Tidal flows at the harbour entrances are particularly fast and can be distinctly choppy and even dangerous with wind over tide. The mean spring tide maximum tide streams at a very fast 6.4 knots. The shallow water over mud and tidal regime leads to significantly warmer waters in the harbour (1or 2 degrees higher than the coastal waters of the eastern Solent). 3.4 There is a mix of uses and slightly different intensity of uses between the harbours. The management of both harbours is particularly geared towards recreational and conservation uses. There are eight sailing clubs adjoining the character area and more on surrounding shores in Chichester. There are several marinas especially on the Chichester side where there is a greater intensity of recreational sailing. Hampshire County 4 Status: FINAL May 2012 Integrated Character Assessment Langstone and Chichester Harbours Moorings tend to be adjacent to main channels and around sailing clubs and marinas, with many drying out at low water. The harbours are an important nursery for many species of fish71 including flat fish (Dover Sole), bream, sprat, herring, pilchard and mullets and in particular bass. There is a closed fishing season in the summer. The harbours have been historically important for oyster growing which has a substantial continental market and also clams. The water quality of Langstone was improved dramatically in 2004 with the construction of a waste transfer tunnel connecting Eastney and Budds Farm sewage works at Havant. The old outfall no longer discharges sewage continuously into the harbour. 4.0 Experiential/Perceptual Characteristics 4.1 Views from within the harbours are varied depending on the state of the tide, but generally expansive. The eye is draw to the landward horizons which are extremely varied from the city skyline of Portsmouth, to the Portsdown Hill and the forts to the wooded shore of Hayling and land between Langstone and Emsworth, with the South Downs in the distance. Views out to the Solent are restricted by the narrow harbour mouths, but the sweeping high landform of the Isle of Wight is an enduring backdrop in views to the southwest. 4.2. Buoyage (channel buoys and marks for navigation) is fairly complex because of the number of branching channels, broad and minor inlets. Larger vessels such as those that ply Bedhampton Wharf can only gain access a few hours either side of high tide. The channels at the heads of the harbours at Emsworth, Langstone, Bedhampton, Farlington and north east Portsea are not navigable or very limited at low water with many dry moorings. The wadeway connecting Northney to the mainland at Langstone is a historical crossing point severed by New Cut. 4.3 The harbour seascape is a contrast of expansive and more enclosed creeks and narrow upper reaches. The character area has a tangible sense of remoteness despite neighbouring large areas of population, especially in Langstone harbour. The backdrop of woods and farmland on the Hayling shore and the mainland of Chichester harbour shores including the hill backdrops of the Isle of Wight and South Downs give the sense of a rural setting. The predominance of natural habitats (mudflats/saltmarsh) and presence of wildfowl species, especially in winter, heighten the sense of naturalness and closeness to wildness. Tranquillity varies with the seasons, time of the week and state of the tide and is particularly influenced by recreational sailing. 5.0 Biodiversity Character 5.1 Langstone Harbour is an internationally important habitat for a range of water fowl and waders, designated as a RAMSAR site, an SPA, SAC and SSSI. It is a tidal basin which at high water resembles an almost landlocked lake. At low water extensive mud flats are exposed, drained by main channels which unite to make a common and narrow exit to the sea from each harbour. The harbour includes one of the largest areas of mixed saltmarsh on the south coast, and extensive cord-grass marsh in an advanced state of degeneration. This is of international importance as a rich intertidal system supporting high densities of intertidal invertebrates and large populations of migrant and overwintering waders and wildfowl. The harbours are amongst the twenty most important intertidal areas in Britain as a summer and Hampshire County 5 Status: FINAL May 2012 Integrated Character Assessment Langstone and Chichester Harbours autumn assembly ground for waders. Langstone Harbour and the adjoining and connected harbours of Portsmouth and Chichester form a single, coherent ecosystem which is among the ten most important intertidal areas for waders in Britain.