See particularly the associated webpages:

| Hurst Spit - new revised version

The Geology of the Beaulieu River Estuary

Solent - Introduction Webpage

INTRODUCTION TO LYMINGTON COAST AND SALTMARSHES

General

INTRODUCTION:

Topographic Maps

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INTRODUCTION:

West Solent - General

The western Solent is the valley of the Solent river, which flowed from west to east, flooded in the Flandrian Transgression. This view is towards the west. Near the left of the aerial photograph is the coast of Christchurch Bay, ending to the southeast at Hurst Spit. The conspicuous dark feature near the bottom of the aerial photograph is Parkhurst Forest. Appearing rather murky in the middle distance is the Newtown estuary where Pleistocene vertebrate remains occur. Bison bones are particularly numerous near the mouth of the estuary and mammoth remains occur too.

For more on Hurst Spit and Hurst Castle see:
Hurst Spit webpage.

For more on Lepe Beach see:
Lepe Beach webpage.

GEOLOGY OF THE LYMINGTON AREA

Geological Maps

INTRODUCTION:

Lymington Estuary - Location, Hydrology and Sediments

The Lymington River drains a wide area of the New Forest, and flows into the West Solent opposite the western end of the Isle of Wight ( Houghton, 1986). The estuary is one the smallest in the Solent and is tidal for approximately 2.3 km. The average salinity at high water is about 30 ppt. ( Houghton, 1986). It was a notable place for the extensive Spartina saltmarshes around the mouth of the estuary, but these are now in quite rapid decline.

Houghton, (1986) examined six samples of silty sediments from around the estuary. They are normal for the region and are dominantly, organic-rich siliclastics. Quartz is high with feldspar very low. On XRD (X-ray diffraction) the quartz/feldspar peak height ratio averages less than 0.02. This is to be expected for this region of derived, Eocene, chemically-mature, siliciclastics. There is a little carbonate but it is very low, averaging 3.3 wt%. Of course, there would no reason to expect high carbonate, except locally as shell debris (e.g. in shell beaches). Coccoliths are present in the fine carbonate but are relatively rare. Organic matter is quite high, averaging 6.8 wt%.

INTRODUCTION:

Saltmarshes - Losses near Lymington

LOCATION - LYMINGTON

Town, Quay and Sea Defences

INTRODUCTION:

Lymington - Extent of Flooding Risk

Most of Lymington Town is built on relatively high ground and is not in normal circumstances at much risk from flooding. Examine the old map of the alluvial deposits (Holocene sediments deposited by sea and river including those of floods and high tides). The 1893 mapping is superimposed on a more modern map and it is obvious that building has, in general, avoided the flood plain. Most of Lymington is on Pleistocene gravel terraces and on the Headon Hill Formation. Of course, with rising sea level the flood limit is likely to be higher in a hundred years time. However, even a 60cm or a one metre rise would not affect more than a very small proportion, in terms of area, of Lymington.

Lymington does not have a notable record for flooding, but this has obviously happened on rare occasions. The general situation may be changing gradually because of slowly rising sea-level and progressive loss of saltmarshes which can retard wave action. There has not been any dramatic or sudden change though.

The low areas of Lymington that are on the flood plain and not far above high tide level, are mostly near the Quay, the Yacht Club and some of the Waterford areas. For most of these areas there is protection by sea defences, although they are not always very high. These defences are in the form of walls, above the quay level, with steel gates in places. Much higher and stronger sea defences extend around the Pennington-Keyhaven marsh area. These sturdy, wide and high banks should resist everything except a "Hurricane Katrina" type event. The marshes seem to be more strongly protected than the town, but there are probably practical reasons for this (access to quays and boats).

Do not use the old geological map, above, for specific information on a road or a building; it is only a general guide. Instead, for official information on flood risk go to the:

Environment Agency - Flooding Website.

Enter "Lymington"

You should obtain a:

flood risk map for Lymington.

You will note that a significant area is shown that could have been flooded on occasions if there were no sea defences. Thus little, if any, of the town is at immediate risk, but some lower parts are dependent on the height and stength of sea defences.

The additional sea wall, which rises above the quay surface level, probably deals with the usual storm events. Whether it is high enough to deal with rising sea-level over the next century is unanswered question. A high rate of 6mm per annum relative sea-level rise has been recorded at Lymington (there is both the present high eustatic rise and a smaller subsidence rate from isostatic rebound).

A further risk factor, but one which applies to other places in the region, is the problem of the eventual return of the one in 250 year hurricane event (like the rare but great hurricanes of 1703 and 1824). This could happen any year. Storm surges of about 3 metres or so above high water mark are possible in extreme events, especially there is the chance coincidence of a hurricane and a high spring tide (as in 1824).

INTRODUCTION:

Flooding in November 1954.

Thus flood records for Lymington are rare. However, A severe storm raged over southern England for in November 1954, and this caused problems. In the nine o'clock news on the BBC radio on the 27th November 1954, it was said that:

"Chesil Beach had been breached in 30 places" (Arkell, 1956). The storm began about 7am on 26 November 1954, and increased in violence all day. The Shambles light-ship recorded winds of gale force 8. The Dorset Daily Echo for the 27 November states that by 11pm on the 26th "Boiling seas, surging over and up through the Chesil Beach swamped the main road.. A stretch from Ferry Bridge to Portland Square lay under water up to a depth of 4 ft. in places... Wyke coastguards counted 30 holes where the seas had worked through the Chesil Beach... A stretch of wall about 40 ft in length skirting the oil tanks was smashed down."

There was damage to Hurst Spit, Hampshire. The following newspaper report presumably refers to this storm. Anonymous (1954). Houses destroyed by floods: terrific seas burst through Hurst Shingle Bank. New Milton Advertiser, 4 December 1954, p.1. Article not seen, but referred to by Delair (2007)

The 1954 storm affected Lymington. There were floods for five nights in succession from 26 to the 30 November 1954 when the sea came over the west bank of the harbour. Here is a statement from a resident about the flooding, reported in Chitty (1983). It refers particularly to a guest house (still there) in King's Saltern Road.

"Then there were the floods in 1954. We had 2 and half feet of water [this might have been in a semi-basement - not clear]: it just trickled over the top step and when the tide went out, so did the water - it went through the floor. They started pumping but they didn't get it all. The Butchers lived opposite us then in Bath Lodge [there is also a photograph of a dinghy being rowed to the entrance of Bath Lodge] and of course Doug was a weatherwise man and said 'There is going to be a very high tide tonight. If it comes up to us can we come over to you? We said, 'Of course' you can'. They already sent the children up to his mother because there was an east wind, a lot of rain water coming down the river and the Spring tides: a formidable combination.

The banks were not half as well built up as they are now and the water began to come over by the Club.... Luckily all our rooms were above the basement so although it was flooded, everything else was perfectly alright, even the kitchen. .. In the houses in Bath Road all the electricity meters were sizzling as they were covered with water." [continues]

LOCATION;

Cage Boom and Pylewell Lake Area
(including Nash Point)

LOCATION - LYMINGTON:

Shell Island, Lymington

LOCATION - LYMINGTON:

Proposed Lymington-Yarmouth Railway Tunnel

Beneath the salt-marshes of the Lymington area there is an interesting sequence of Pleistocene Gravel of the Solent River, overlain by Holocene alluvial muds with the Neololithic Peat. The sequence was originally revealed in old borehole investigations for a proposed railway tunnel from Lymington across to the Isle of Wight. Fortunately, the tunnel has never been excavated, allowing the Isle of Wight to retain its relative isolation. As a result the natural western coast of the Isle of Wight has not been destroyed by the development of major holiday resorts. (Literature references and a partial cross-section will be given later. )

LOCATION - EAST OF LYMINGTON:

Boldre Foreshore Nature Reserve - Saltmarshes

LOCATION - EAST OF LYMINGTON:

Boldre Foreshore Nature Reserve - Saltmarshes - Near Lisle Court

LOCATION - EAST OF LYMINGTON:

Boldre Foreshore Nature Reserve - Saltmarshes -
Tanners Lane

The Lymington Saltmarshes, east of the town are undergoing degeneration and erosion. This is most marked at Tanners Lane, near Pitts Deep (map ref: SZ 364953).

LOCATION - WEST OF LYMINGTON:

Keyhaven Saltmarshes(Lymington-Keyhaven Nature Reserve)

Much filamentous algae of Enteromorpha type has been washed up at the landward margin of the Keyhaven saltmarshes, as seen in early July 2008. It is still green on the seaward side of the accumulations but is bleached almost white on the higher, landward side. Much Enteromorpha can be seen in situ on the outer mudflats and on channel margins of the Keyhaven saltmarshes, particularly where there has been erosion and destruction of Spartina marsh.

Similar accumulations of Enteromorpha were noticed in the summer of 2007 at Brands Bay in Poole Harbour. See:
Studland, Poole Harbour Side, webpage.

At the time of the Olympics in China in summer 2008 there is a major problem with similar filamentous algae at Qingdao and it has become international news. See the webpage Tackling Qingdao's Invading Algae. Thick green algae has overwhelmed the Qingdao coastline. It is knee-deep. 10,000 recruits of the People's Liberation Army have been deployed to remove it.

LOCATION - WEST OF LYMINGTON:

Pennington Marshes - Brackish Lagoons

OVERVIEW:

Future Changes in the Mainland Coast of the West Solent

The mainland coast of the West Solent is changing from a varied coastline, originally with several small harbours and inlets in addition to harbours still surviving. It once had extensive mud flats but in the 20th century extensive Spartina saltmarshes developed. These are now eroding and declining fast. Mud flats have greatly reduced in width with coastal squeeze from rising sea-level (i.e. steepening shores - low water mark approaching high water mark in location terms). Cliff erosion on the north shore of the West Solent is limited now but is increasing and will increase greatly. In particular, the saltmarshes east of Lymington will disappear and fresh cliffs of Pleistocene gravel will develop. Such cliffs will then provide masses of shingle which will move with longshore drift northeast into large spits. One of these will close or partially close the Beaulieu River mouth. The north shore of the West Solent will become a coast of shingle beaches, somewhat like those of the Hayling Island, Bracklesham Bay coasts in the more open, Spithead region. This trend towards cliffs, shingle beaches and spits will happen in any case with rising sea-level. The change in this direction would be more drastic if Hurst Spit were to be destroyed by rising sea levels and hurricanes in the future.

Bibliography of the Geology of the Solent - General Section - Undivided This is a list of Solent Estuarine System references, not separated under topics. It is not comprehensive and the user is referred to the continuation - the alphabetical section below for more complete coverage .

This is divided into sections such as Bracklesham Group, Radionuclides, Saltmarshes etc. and is more complete. Some topics such as material relating to the Isle of Wight are only covered briefly and full lists are in other bibliographies (although not necessarily available here).

I very much appreciate discussion in the field with Toru Tsuzaki and on many occasions with Yining Chen. I very much appreciate the receipt of helpful historic information from Jeremy Greenwood.

Disclaimer: Geological fieldwork involves some level of risk, which can be reduced by knowledge, experience and appropriate safety precautions. Persons undertaking field work should assess the risk, as far as possible, in accordance with weather, conditions on the day and the type of persons involved. In providing field guides on the Internet no person is advised here to undertake geological field work in any way that might involve them in unreasonable risk from cliffs, ledges, rocks, sea or other causes. Not all places need be visited and the descriptions and photographs here can be used as an alternative to visiting. Individuals and leaders should take appropriate safety precautions, and in bad conditions be prepared to cancell part or all of the field trip if necessary. Permission should be sought for entry into private land and no damage should take place. Attention should be paid to weather warnings, local warnings and danger signs. No liability for death, injury, damage to, or loss of property in connection with a field trip is accepted by providing these websites of geological information. Discussion of geological and geomorphological features, coast erosion, coastal retreat, storm surges etc are given here for academic and educational purposes only. They are not intended for assessment of risk to property or to life. No liability is accepted if this website is used beyond its academic purposes in attempting to determine measures of risk to life or property.

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