Series details: CRDA/10

The Coast Protection Survey of England (CPSE) of the former Ministry of Agriculture, Fisheries and Food (MAFF) was carried out for the first time in 1993-94. Annual updates for 1995, 1996 and 1997 were conducted in 1995-96, 1996-97 and 1998 respectively. The survey was originally commissioned in 1993 to gather information to help MAFF discharge its functions under the Coast Protection Act 1949 in regard to coast protection defences. These are defences designed to protect the coast against erosion and encroachment by the sea. MAFF's decision to conduct the CPSE was prompted by the publication in 1992 of the results of a survey of sea defences (i.e. defences against flooding by the sea) conducted by the former National Rivers Authority (NRA), and by the publication of a report on coastal defences in England by the House of Commons Public Accounts Committee. The aim of the original survey was to gather data on the location, extent, nature, adequacy and state of repair of coast protection defences along the English coastline, with the primary purpose of identifying requirements for defence works within the next 3-5 years.1 The survey also aimed to examine unprotected lengths of coast identified as "significantly eroding", i.e. those with "substantial [land] assets which may reasonably require protection works within the next 10 years".2 It was intended that data from the CPSE would help MAFF assess priorities for future expenditure on coast protection, and would inform discussions between MAFF's Regional Engineers and coast protection authorities about future programmes of capital works.3

Sir William Halcrow and Partners Ltd, an engineering consultancy, was appointed as project manager/lead consultant to co-ordinate the original survey. The gathering of data was delegated to three other engineering consultancies who were appointed by MAFF as "associate consultants". These associate consultants were assigned responsibility for five geographical areas based on the areas covered by MAFF's Regional Engineers. The areas covered and the associate consultants involved were:

1. York Area/NW (Scottish border to the River Dee): Mouchel Consulting Ltd
2. York/Lincoln Areas NE (Scottish border to the Wash): Posford Duvivier International Consulting Engineers
3. Cambridge Area (King's Lynn to Southend-on-Sea): Mott MacDonald
4. Tunbridge Wells Area (Thames estuary to the Isle of Wight): Posford Duvivier International Consulting Engineers
5. Taunton Area (Dorset, Devon, Cornwall, Somerset and Bristol to the Severn): Mouchel Consulting Ltd 4

The original survey covered 1,018 km of coast line out of a total coastal area of 3763 km. 860 km of predominately man-made coast protection defences were surveyed, together with 158 km of naturally defended coast. 134.8 km of natural coast were identified as significantly eroding. Data was gathered on both "defence lengths" (i.e. lengths of coast) and "defence elements" (the different types of defences within each length of coast).5

Most of the data gathering and field work by associate consultants was done in the second half of 1993. They were required to input their data into databases using a database format supplied by Halcrow. Associate consultants were also required to produce at least one colour photograph of each defence element, at least one representative cross-section of each defence, and outline maps showing the location and extent of defence lengths and defence elements. The data, cross-sections, photographs and outline maps were submitted to Halcrow and were used to produce a report for each region of the survey. These reports set out the objectives in carrying out the survey, the methodology used by the associate consultant and summary findings for each survey area. They also included appendices of photographs and cross sections of defences, printouts of data for defence elements and defence lengths, lists of contacts consulted during the survey, and outline maps. An amalgamated database of survey data was produced by Halcrow from the data submitted by the associate consultants.6

Draft reports for each survey area were submitted by Halcrow to MAFF in March 1994. Following comments from MAFF, final survey reports were produced by Halcrow which were sent for comments to maritime local authorities in late 1994. In some cases information in the survey database was updated in response to comments received from local authorities.7 An eight page summary report setting out the principal findings of the original survey was published by MAFF in 1994: a copy of this report has been transferred to NDAD (see the Dataset Documentation Catalogue, reference CRDA/10/DD/2/1).

After the original survey the CPSE database continued to be maintained by Halcrow under contract to MAFF. A copy of the database was held at FCDE in London, although printouts of the data tended to be used for daily reference. Printouts were held by the Regional Engineers in MAFF's regional offices and were used by them to assess applications for grants for coast protection schemes. Copies of the database were supplied to other bodies (e.g. universities, maritime local authorities). Digital maps derived from data in the CPSE database were maintained by Halcrow on a Geographical Information System (GIS). This GIS data was also held at FCDE, although it was not generally used; by 2001 the GIS data at both MAFF and Halcrow had ceased to be maintained and was thought to be redundant.8 For further information on the system history of the CPSE database, see Hardware, Operating system and Application software.

Three annual updates of the CPSE were conducted by Halcrow through surveys of maritime local authorities and other major bodies responsible for coast protection defences (e.g. Railtrack plc, Associated British Ports). The first two updates (1995 and 1996) required a general update of information relating to defence elements. The 1996 update also required additional information relating to defence elements whose condition had been classified as "Class 4", i.e. as needing significant remedial works, with capital works probably required within the next five years. For the 1997 update it was decided to focus entirely on Class 4 defence elements.9 This decision was made to lessen the burden on local authorities in responding to the survey, and because of a realization that there had been relatively little change in much of the information held about coast defences.10 For each update, Halcrow produced new tables by copying data from the most recent survey and then updating and amending it as necessary. Data from the earlier updates and from the original survey was preserved and was not overwritten. Additional tables were created for the data relating to "Class 4" defence elements which was gathered in the 1996 and 1997 annual updates.11 For information on how data was gathered in the original CPSE and subsequent updates, see How data was originally captured and validated.

In January 1999 MAFF informed NDAD that it would not be commissioning a 1998 update and would review the future of the CPSE during 1999. No further updates were carried out and the survey is believed to have been discontinued.12

It should be noted that in the area of sea defences (i.e. defences against flooding from the sea rather than coastal erosion), the counterpart of the CPSE database was the Sea Defence Survey database maintained by the Environment Agency, which included details of the condition of sea defences along the Welsh and English coastlines. This survey was first conducted in 1991 by the Environment Agency's predecessor, the National Rivers Authority, and was updated annually.13 A separate survey of coastal defences in Wales was conducted by the Welsh Office (see Related units of description).

The Ministry of Agriculture, Fisheries and Food had overall responsibility for policy on flood defence and coast protection in England, and administered the legislation which allowed flood and coastal defence works to be carried out. This included oversight of the work of local authorities, internal drainage boards and the Environment Agency in planning, maintaining and operating defence measures; the provision of advice and guidance to these authorities; the funding of research into flood defence and coast protection; and grant-aid for capital defence projects. Within MAFF, flood and coastal defence functions were discharged by Flood and Coastal Defence with Emergencies Division (FCDE) when the Coast Protection Survey of England datasets were transferred to NDAD in 1998 and 2001. At the time FCDE was responsible for the survey, which was originally commissioned by FCDE's predecessor, Flood Defence Division.

As previously noted (see Aim and purpose), the original survey was co-ordinated on MAFF's behalf by Sir William Halcrow and Partners. Data gathering was carried out by three associate consultants: Mouchel Consulting Ltd, Posford Duvivier International Consulting Engineers, and Mott MacDonald. Halcrow itself conducted the three subsequent updates of the CPSE.

Following the 2001 general election, MAFF was replaced by the Department for Environment, Food and Rural Affairs, which also inherited MAFF's flood and coastal defence functions. Flood and coastal defence policy in Wales is the responsibility of the National Assembly for Wales, exercising powers formerly belonging to the Welsh Office: see the Administrative History of the Welsh Office. For further information about the history of MAFF and Flood and Coastal Defence with Emergencies Division (and its predecessors), see the Administrative History of the Agricultural Departments.

NDAD holds datasets for the original CPSE survey of 1993-94 and the 1995, 1996 and 1997 annual updates. Each dataset contains data on defence lengths and defence elements, while the datasets for the 1996 and 1997 updates contain data on "Class 4" elements. The data is held, respectively, in Length, Element and Form_d tables.

The Length tables contain general information about coast protection defences and unprotected lengths of coast identified as "significantly eroding". This was done by dividing the coast into defence lengths, corresponding to lengths of coast identified as having one or more coast protection structures and/or significantly eroding coastline. Divisions between defence lengths were made according to the following criteria:

• Changes in the ownership of the primary defence within a defence length.
• Significant changes in the form of the primary defence.
• The limits of unprotected sections of coast determined to be significantly eroding.
• Significant changes in the geology or erosion rates of unprotected, significantly eroding coastline.14

At the time of the original survey associate consultants were also instructed to take into consideration the start and finish of flood defences in the NRA's Sea Defence Survey (see Aim and purpose). However, these were not to be regarded as definitive, and when establishing defence lengths preference was to be given to locally recognized limits of defences obtained from council officials and/or MAFF's Regional Engineers.15

The Length tables in the CPSE datasets contain the following information:16

• A numerical code for each defence length in the form abb/ccdd, where 'a' identifies the MAFF region of the survey (i.e. York, Lincoln, Cambridge, Tunbridge Wells and Taunton); 'bb' identifies the region used in the NRA's Sea Defence Survey; 'cc' is a code for the relevant local authority; and 'dd' is a unique identifier for each defence length.
• The principal location of the defence: e.g. the name of the nearest town, village or feature.
• The date when a site visit was conducted at the time of the original survey, the associate consultant which conducted the visit, and the initials of the staff member involved.
• Ordnance Survey grid references representing the start and end points of the uppermost main primary feature of the defence length: e.g. the crest line of the primary wall.
• The length in kilometres to two decimal places between the start and end points of the primary feature of the defence.
• The "asset type" of the defence length, i.e. the main components of the defences in each coastal length (seawall, embankment, groynes, etc), including whether the coast was "shore" (i.e. a naturally eroding coastline). Up to four possible components could be specified. A separate field (Natural) records if the primary defence was a natural defence.
• The crest level of the primary defence, i.e. the elevation of the crest of the defence in metres relative to Ordnance Datum Newlyn.
• The degree of exposure of the defence (i.e. its openness to prevailing storm conditions).
• The "design standard" of the defence, defined as "the return period [in years] for which the structure was designed" (in practice this information is usually missing).17
• The wave height in metres for which the defence was designed.
• The erosion rate for lengths of unprotected cliff and shoreline identified as "significantly eroding".
• A classification of the principle type of land use behind the defence length within the zone deemed to be at risk of erosion within the next 50 years.
• Estimates of the numbers of domestic and commercial properties at risk within the 50-year erosion zone.18
• The reference port, i.e. the secondary port most applicable for the prediction of tide levels, identified from Admiralty Tide Tables.
• The highest and lowest astronomical tides for the defence length, i.e. the highest and lowest water levels "which can be predicted to occur under average meteorological conditions and any combination of astronomical conditions".19

Users of the Length tables should note that the 1995 and 1996 updates of the CPSE only required respondents to update data on defence elements, while the 1997 update only required the updating of data on "Class 4" elements. Information on defence lengths was not systematically updated. Consequently the Length tables in the datasets for the 1995, 1996 and 1997 updates largely reflect data gathered in the original (1993-94) survey. Any differences will mainly represent changes made by Halcrow as a result of new information received about defence elements or Class 4 defences.20

The Element tables in the CPSE datasets provide more specific information about the types of coast protection defences within defence lengths. A defence length might contain one or more defence elements which could sit upon each other, abut each other or be completely separate. Defence elements were distinguished from each other according to changes in defence lengths; significant changes in structure (excluding ad-hoc repairs); changes in cross-section; changes in ownership; differing construction dates (in the case of similar forms of construction known to have been constructed more than two years apart); and variations in condition and residual life. Differentiation on construction date alone was considered inappropriate in the case of structures which were more than 10 years old. As in the case of defence lengths, associate consultants were required at the time of the original survey to consider the divisions into defence elements that were used in the NRA's Sea Defence Survey, but to give greater weight to locally recognized divisions.21

The Element tables provide the following information:22

• The code for the defence length plus a two digit sub code for each defence element.
• Ordnance Survey grid references representing the start and end points of the defence element, and the length between these points in kilometres (to two decimal places).
• The type of structure which the defence element represented (e.g. a bastion, embankment, revetment, wall).
• The major constituent material of the defence element (e.g. block, boulder, masonry).
• The dominant geology/sedimentology of the element (e.g. metamorphic, igneous, sand), the angle of slope to the horizontal, and the appearance of the cliff (weathered, friable, etc), in cases where the "structure" of the defence element was described as "cliff/scarp" or "beach ridge".
• For man-made defence elements, a classification of the element's condition (i.e. its overall state of repair).
• The type of foreshore in front of the defence element (e.g. sand, shingle, clay), and an assessment of how the foreshore was changing with time (e.g. eroding, stable), based as far as possible on the trend over the most recent five-year period.
• The level of the foreshore in front of the defence element, and an assessment of the degree to which the integrity of the coast protection structure was dependent on a high-level foreshore.
• The year or the approximate decade when the element was originally constructed or reconstructed. The date of reconstruction rather than the date of construction was meant to be recorded if reconstruction was substantive (generally in lengths not less than 250 metres), and residual life was expected to be in excess of 20 years.
• An estimate of the residual life of the defence element in years.
• The authority, council or body responsible for maintaining the defence element or for significantly eroding sections of coastline, and whether the element was maintained by a local authority.
• A classification of the priority of the defence element, calculated by a formula involving the purpose of the defence element, its residual life in years, and the benefit to cost ratio of the defence element. The latter was calculated by assessing the value of the erosion damage avoided by having the defence against the cost of building the defence.23
• A classification of the urgency of maintenance works, based on the residual life of the defence element, whether it was in an urban or rural area, and whether the value of damage caused would be significant.
• Whether a photograph of the defence element had been supplied at the time of the original (1993-94) survey.
• Two supplementary report description fields where additional information about a defence element could be recorded (e.g. extra information about the construction of the defence and subsequent repairs).

The 1995 and 1996 annual updates of the CPSE required local authorities and other respondents to update the data on defence elements which had been gathered in the original survey or in the previous update. However, in the 1997 survey respondents were only asked to update information on "Class 4" elements, the data for which is held in the 1997 Form_d table (see below). Any differences between the Element tables in the 1997 dataset and the 1996 dataset will either reflect consequential changes made by Halcrow as a result of new information about Class 4 elements; or changes resulting from the late return of 1996 forms; or the voluntary provision of extra information by respondents (see How data was originally captured and validated).

The Form_d tables in the datasets for the 1996 and 1997 updates contain the data which respondents were asked to supply about defence elements whose condition had been classified as "Class 4": i.e. deteriorating defences likely to need capital works within the next five years (the most serious condition classification in the Element tables). In both sweeps respondents were asked to update information on elements which had previously been categorised as Class 4, and to include data on elements which had entered the Class 4 category since the last survey. The Form_d tables provide the following details:

• The code for the defence length plus the sub-code for the defence element.
• The "policy status" of the element - i.e. the maintenance policy of the operating authority towards the element.
• If the policy status indicated that the structure had been abandoned as a coastal defence or that capital works were planned in the next five years, the data was meant to include the year that the defence was abandoned and the year that capital works were due to start. A "year" is sometimes also provided for elements with other policy status categories.
• The estimated cost of capital works if works were planned within the next five years. (This information is often missing, and "cost" is sometimes provided for elements with other policy status categories).
• Any additional notes relating to the defence element.24

Further information about the contents of the datasets which have been transferred to NDAD is given in the catalogues of individual datasets: see Links to dataset catalogues.

As the Coast Protection Survey of England is believed to have been discontinued (see Aim and purpose), no further transfers of data are expected.

The Coast Protection Survey of England datasets and most items of dataset documentation are public records under the Public Records Acts 1958 and 1967. The Public Record Office has assigned these datasets and documents the class reference MAF 406. Some documents are not public records: for details of these documents, see the Dataset Documentation Catalogue.

The Coast Protection Survey of England datasets and related dataset documentation are open without restriction. Data is available for browsing on demand by users of NDAD and does not have to be booked in advance.

The Coast Protection Survey of England datasets and related dataset documentation are Crown Copyright. Copies may be made for private study and research purposes only.

The Coast Protection Survey of England datasets are not subject to registration under the Data Protection Act.

The language of the materials is English.

Documents relating to the Coast Protection Survey of England have been transferred to NDAD and are listed in the Dataset Documentation Catalogue.

In 1992 the Welsh Office began work on its own survey of coastal defences (including coast protection defences and sea defences) and the condition of coast protection defences in Wales. A dataset for this survey incorporating data gathered down to 1996 has been transferred to NDAD, together with related documentation: for further details, see the Series Catalogue for the Coastal Survey - Wales. NDAD has also received datasets from the annual reports submitted to MAFF by Internal Drainage Boards in England: see the Series Catalogue for the Internal Drainage Board Database.

A summary of the findings of the original (1993-94) Coast Protection Survey of England was published by MAFF: Ministry of Agriculture, Fisheries and Food, Coast Protection Survey of England: Summary Survey Report (London: MAFF, 1994), reference PB 2906. A copy of this publication has been transferred to NDAD: see the Dataset Documentation Catalogue, reference CRDA/10/DD/2/1.

At the time of the original survey (1993-1994) the associate consultants are believed to have used IBM or compatible PCs. Halcrow ran the Informix version of the CPSE database on UNIX work stations in a local network, and is thought to have run the later Access versions of the database on IBM or compatible PCs (see Application software). MAFF is believed to have run the CPSE database on IBM or compatible PCs (in 2001 MAFF used a Compaq Deskpro EX series to run the Access 97 version).

The associate consultants involved in the original survey are believed to have used DataEase (see Application software) on Microsoft DOS version 5.0. Halcrow ran the Informix version of the CPSE database on UNIX, and the Microsoft Access versions on Windows; MAFF used DOS with the Oracle version, Microsoft Windows 3.1 with the Microsoft Access 2.0 version, and Windows 98 with the Access 97 version.

The associate consultants who gathered the data at the time of the original CPSE survey input the data into a database established by Halcrow in DataEase version 4.2 (manufactured by Sapphire International, 13-19 Curtain Road, London). When the data was transferred to Halcrow, it was migrated into an Informix database manufactured by Informix Software Inc, Menlo Park, California, USA. This was linked in turn to a Geographical Information System (GIS) using Intergraph software manufactured by Intergraph Corporation, Huntsville, Alabama, USA. The CPSE data was exported by Halcrow to MAFF in Oracle. MAFF's Oracle database (manufactured by Oracle Corporation, Redwood Shores, California, USA) was also linked to an Intergraph GIS.

The CPSE database continued to be held at Halcrow in Informix and at MAFF in Oracle until early 1998, when Halcrow migrated the database on MAFF's behalf to Microsoft Access 2.0 and Microsoft Access 97. Different versions of Access were used because MAFF and some other recipients of the data (e.g. some maritime local authorities) required Access 2.0, while others wanted it in Access 97. NDAD has produced analyses (using Access's "Documenter" facility) of copies of the Access 2.0 and Access 97 databases which were transferred to NDAD in March 1998 and January 2001, respectively (see the Dataset Documentation Catalogue, reference CRDA/10/DD/4/1/1-2). These indicate that the Access 2.0 database was originally created in February 1998; the components of the Access 97 version (tables, queries, forms, macros) were created between 1998 and 2000, though most of the tables were originally created in 1998. The Informix and Oracle databases are thought to have been maintained for a time as the Access versions of the database were not linked to the GIS systems at MAFF and Halcrow. However, data from the 1997 update was only entered into Access. By 2001 the GIS systems at MAFF and Halcrow had ceased to be used and were thought to be redundant. MAFF had also replaced its Access 2.0 version of the database with the Access 97 version, including data from the 1997 update.25

Little information is available regarding the user interface of the versions of the CPSE database which preceded the conversion to Microsoft Access. The Informix database used by Halcrow is believed to have been command-line driven. It also appears that Halcrow established a user interface for MAFF with standardized queries when the database was originally transferred to MAFF in Oracle.26 The Microsoft Access 2.0 version of the database allowed the data to displayed as forms or as tables, and to be input through the on-screen forms or by adding to the columns of data when displayed as tables. The Access 97 version had a considerably more complex interface, involving a hierarchy of "switchboards" (a type of form created to assist navigation within an Access 97 database) and other forms. These allowed users to view and query data by local authority, MAFF region and coastal group, and view lookup tables. A number of items of system documentation which reflect the operation of the Access 2.0 and Access 97 databases are available via the Dataset Documentation Catalogue.

There are a number of differences in the structure of the CPSE datasets, which reflect the fact that the datasets were transferred to NDAD at different times and from different versions of the CPSE database.

Datasets for the original survey, the 1995 update, the 1996 update and the lookup table for principal type of land use were transferred from MAFF to NDAD in March 1998 in Microsoft Access 2.0, the format in which MAFF held the CPSE database at that time (see Application software). NDAD received a copy of the entire database which consisted of Length and Element tables for each year of the survey. The Length tables for each year were linked in one-to-many relationships to the Element tables via the def_code field in the Length tables and the defence_code and sub_code fields in the Element tables (def_code and defence_code contain the codes for defence lengths, and sub_code contains sub-codes for defence elements). No relationships had been defined between the Element and Length tables across different years of the Survey: for a copy of the Microsoft Access relationships window showing the relationships which had been defined between the tables, see the Dataset Documentation Catalogue, reference CRDA/10/DD/5/1/2. The single lookup table, l_princip_type, explains the values used in the principal_type field in the Length tables (recording the principal type of land use within the 50-year erosion zone). The dataset for the 1996 update did not include the Form_d_96 table, which at that time had not been transferred to MAFF from Halcrow.

In January 2001 NDAD received the dataset for the 1997 update from MAFF. This came via a copy of the Access 97 version of the CPSE database which also included data for the earlier sweeps of the survey. As in the Access 2.0 version, there were Element and Length tables for each year of the survey. However, the database also included Form_d tables for the 1996 and 1997 updates, and a number of other tables which had not been present in the earlier version: a large number of lookup tables defining values used in the Element, Length and Form_d tables; lookup tables for local authorities, coastal groups and MAFF regions, which related to the data viewing and querying functions; a lookup table (CrossRefCouncilGroup) which connected coastal groups and local authorities; and a Switchboard Items table relating to the operation of the "switchboards" and forms which provided the database's user interface (see User interface). A copy of the Microsoft Access relationships window shows the relationships which had been defined between the tables in the database: see the Dataset Documentation Catalogue, reference CRDA/10/DD/5/1/1.

As in the Access 2.0 database, the Length and Element tables were linked in one-to-many relationships by def_code in the Length tables and defence_code and sub_code in the Element tables. Similarly, the Element_95 and Element_96 tables were linked in one-to-one relationships to Form_d_96 via defence _code and sub_code. However, it is also clear that some table relationships which could have been defined had not been: e.g. between the Element, Length and Form_d tables for the 1997 update. There were no direct links between the data tables and the "codelists" (lookup tables), which were viewed separately. The forms in the database also allowed users to view combinations of data in ways that went beyond the relationships which had been defined between the tables: e.g. the FORM D 1997 form (Dataset Documentation Catalogue, reference CRDA/10/DD/4/3/4/6) allowed data on "Class 4" defences from the 1997 update to be viewed in conjunction with element data (as a subform) from the original survey and each subsequent update.

The Form_d table for the 1996 update has been added to the 1996 CPSE dataset alongside the Length and Element tables received in 1998. The lookup tables received as part of the Access 97 database have been added to the dataset for the 1997 update, while data from the Switchboard Items table has been made available in the Dataset Documentation Catalogue, reference CRDA/10/DD/4/2/1.

The CPSE datasets are closed, in the sense that new tables were created for each year of the survey. Data in the tables for one year of the survey was not overwritten by data received in the next annual update.

During the original survey in 1993-1994 data was gathered by the three associate consultants using the following methods:

• Through desk reviews of published sources (e.g. Admiralty Tide Tables) and information already held by the associate consultants.
• By obtaining copies of information held by maritime local authorities and other bodies responsible for coast protection defences.
• By visits to maritime local authorities and other bodies.
• Through site visits by staff of the associate consultants to inspect coast protection works, take photographs and prepare cross sections of defences.27

Data gathered by the associate consultants was submitted to Halcrow for comments. In some cases this led Halcrow to seek clarification or further details from the associate consultant.28 Feedback was also received from maritime local authorities following the circulation of reports for each survey region (see Aim and purpose).

The annual updates of the CPSE were conducted by Halcrow by sending forms to maritime local authorities and other major bodies responsible for coast protection defences. In 1995 three forms were issued:

• Form A, to gather details of new coast protection structures or changes to existing structures due to capital works or significant maintenance since the original survey.
• Form B, to record alterations to existing man-made defence elements due to changes in the condition of the structure itself or its immediate environment (rather than through new works or maintenance).
• Form C, to record previously unclassified and unprotected frontages now identified as requiring new protection works within the next 10 years.29

In the 1996 annual update these forms were joined by a Form D, to gather information on defence elements whose condition had previously been classified as "Class 4", and to allow respondents to identify elements which had been newly classified as Class 4.30 A different set of forms was sent out in the 1997 update, reflecting the decision to focus on Class 4 elements. These included:

• Form D.1, to record alterations to existing Class 4 defence elements due to changes in the condition of the structure itself or its immediate environment (rather than through new works or maintenance).
• Form D.2, to record changes in the maintenance policies towards existing Class 4 defences.
• Form D.3, to record defence elements which had entered the Class 4 category since the 1996 update, and any associated maintenance policies.
• Form D.4, to record changes due to capital works or significant maintenance to defence elements which had been previously classified as Class 4.31

Copies of the forms used in the 1995 and 1996 updates, and the guidance notes issued in the 1995, 1996 and 1997 updates can be consulted via the Dataset Documentation Catalogue.

In 1995 and 1996 survey forms were sent out by Halcrow around November of the year of the update and were to be returned by the following February. A different policy was adopted for the 1997 annual update: forms were sent out in March 1998 and were due to be returned by 6 April 1998. Returns for the 1995 and 1996 updates were supposed to reflect the situation on 1 November 1995 and 1 November 1996 respectively. In the 1997 update respondents were asked to provide information on Class 4 defence elements as they stood on 1 March 1998 (however, the survey was still known as "1997 annual update"). Although the 1997 update only required details of Class 4 defences, some local authorities provided voluntary updates of their element and length data, and this information was incorporated into the 1997 data tables. The dataset for the 1997 update also includes data from some returns from the 1996 update which had been received after the "cut-off" point for that sweep.32

In the 1995 and 1996 updates completed survey forms were checked by Halcrow on receipt using validation checklists and by plotting any significant changes onto maps. Survey respondents were then contacted for further information where there were uncertainties or ambiguities in the data.33 An example of a validation checklist used in the 1996 survey has been transferred to NDAD: see the Dataset Documentation Catalogue, reference CRDA/10/DD/3/1996/5.

As with any survey data, the CPSE datasets reflect the availability of information at the time that the data was gathered: e.g. in the Length tables, the "design standard" of the defence is rarely recorded as this information was generally not available. The annual updates of data were also dependent on forms being completed and returned by the bodies to which they were sent. The response rate to the questions relating to Class 4 defences in the 1996 survey is thought to have been relatively low (30-40%).34

Details of the content and transformation validation checks performed by NDAD on each CPSE dataset are recorded in the catalogues of individual datasets: see Links to dataset catalogues.

Dataset catalogues provide more detailed information about individual datasets, and are currently available for the following dataset(s):

1. Dataset Documentation Catalogue, reference CRDA/10/DD/2/1, p. 1.

2. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, p. 47.

3. Dataset Documentation Catalogue, reference CRDA/10/DD/2/1, p. 8.

4. Dataset Documentation Catalogue, reference CRDA/10/DD/2/2, p. 1; web site of Posford Duvivier International Consulting Engineers, page on "Coast Protection Survey of England: Maff [sic] York/Lincoln and Tunbridge Wells Regions" (http://www.posford.co.uk/lincoln.htm) consulted on 20 May 1998.

5. Dataset Documentation Catalogue, reference CRDA/10/DD/2/1, pp. 6-7.

6. Note of telephone conversation between NDAD and Halcrow Maritime on 22 May 1998; see also Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, pp. 57-60.

7. Note of telephone conversation between NDAD and Halcrow Maritime on 22 May 1998.

8. Notes of telephone conversations between NDAD and Flood and Coastal Defence with Emergencies Division, MAFF on 8 June 1998, 30 January 2001 and 19 April 2001; note of telephone conversation between NDAD and Halcrow Maritime on 16 March 2001.

9. Dataset Documentation Catalogue, references CRDA/10/DD/3/1995/1, CRDA/10/DD/3/1996/1, and CRDA/10/DD/3/1997/1-2.

10. Note of telephone conversation between NDAD and Halcrow Maritime on 21 May 1998.

11. Notes of telephone conversations between NDAD and Halcrow Maritime on 22 May 1998 and 9 June 1998.

12. Note of telephone conversation between NDAD and Flood and Coastal Defence with Emergencies Division, MAFF on 5 January 1999.

13. Note of telephone conversation between NDAD and the Environment Agency on 22 April 1998 regarding the Coastal Survey - Wales database (CRDA/6).

14. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, p. 42.

15. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, p. 42.

16. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, pp. 42-48; see also the descriptions of the Length tables which are linked to the Dataset Catalogues for CRDA/10/DS/1/1-4.

17. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2 p. 46.

18. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, pp. 47-48 refers to a "60 year erosion zone" in respect of the principal type of land use and the number of domestic and commercial properties at risk. The original field descriptions accompanying the CPSE datasets indicate that the data relates to a 50 year erosion zone. MAFF have said that the latter definition was probably used when the data was gathered in the original survey: note of telephone conversation between NDAD and Flood and Coastal Defence with Emergencies Division, MAFF on 9 June 1998.

19. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, p. 48.

20. Dataset Documentation Catalogue, references CRDA/10/DD/3/1995/1, p. 2; CRDA/10/DD/3/1996/1, p. 2; CRDA/10/DD/3/1997/2; notes of telephone conversations between NDAD and Halcrow Maritime on 22 May 1998 and 16 March 2001.

21. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, p. 49; CRDA/10/DD/3/1995/1, p. 2-3.

22. Dataset Documentation Catalogue, reference CRDA/10/DD/1/2, pp. 49-57; reference CRDA/10/DD/3/1995/1; reference CRDA/10/DD/3/1996/1. See also the descriptions of the Element tables which are linked to the Dataset Catalogues for CRDA/10/DS/1/1-4.

23. Note of telephone conversation between NDAD and Flood and Coastal Defence with Emergencies Division, MAFF on 9 June 1998.

24. Dataset Documentation Catalogue, reference CRDA/10/DD/3/1996/1; reference CRDA/10/DD/3/1997/1; see also the descriptions of the Form_d tables which are linked to the Dataset Catalogues for CRDA/10/DS/1/3-4.

25. Information about the system history of the CPSE is derived from the transfer form received for the first three datasets (CRDA/10/DS/1/1-3); the Data Owner transfer form for the final dataset (CRDA/10/DS/1/4); Dataset Documentation Catalogue, reference CRDA/10/DD/1/1, p. 33; notes of telephone conversations between NDAD and Halcrow Maritime on 21-22 May 1998, 9-10 June 1998, 13 August 1998 and 16 March 2001; notes of telephone conversations between NDAD and Flood and Coastal Defence with Emergencies Division, MAFF on 8 June 1998, 13 December 2000 and 19 April 2001.

26. Notes of telephone conversation between NDAD and Halcrow Maritime on 9 June 1998.

27. Dataset Documentation Catalogue, reference CRDA/10/DD/2/2, pp. 3-6.

28. Note of telephone conversation between NDAD and Halcrow Maritime on 22 May 1998.

29. Dataset Documentation Catalogue, reference CRDA/10/DD/3/1995/1, p.1.

30. Dataset Documentation Catalogue, reference CRDA/10/DD3/1996/1, p. 1.

31. Dataset Documentation Catalogue, reference CRDA/10/DD/3/1997/1, p. 1.

32. Notes of telephone conversations between NDAD and Halcrow Maritime on 21 May 1998, 9 June 1998 and 16 March 2001; Dataset Documentation Catalogue, reference CRDA/10/DD/3/1995/1, p. 1; CRDA/10/DD3/1996/1, p. 1; CRDA/10/DD/3/1997/1, p. 1; CRDA/10/DD/3/1997/2.

33. Note of telephone conversation between NDAD and Halcrow Maritime on 22 May 1998; Dataset Documentation Catalogue, reference CRDA/10/DD/3/1996/5.

34. Notes of telephone conversations between NDAD and Halcrow Maritime and NDAD and Flood and Coastal Defence with Emergencies Division, MAFF on 9 June 1998.