Coast and River

We specialise in surveys of rivers and coastal areas for the Environment Agency, Local Authorities and Engineering Consultants.

COAST

EDI Surveys has been working with the Environment Agency surveying the East Anglian coastline since 1991 and we are currently contracted to do so for 2016 to 2021 and we are also monitoring the south coast from Chesil beach to Start Point over the same period for Teignmouth DC. We have also carried out similar work in Qatar.

Profiles are surveyed using GNSS at known points along the coast and repeated 2-4 times per year to monitor erosion and deposition. Data is output as TXT files in the clients specified format including SANDS. The raw site data can be used to produce a wide variety of outputs. Other surveys include level grids (typically 5m spacing) and sea defence surveys.

See a typical cross section here

RIVER

The majority of channel surveys consist of detailed cross sections at set intervals (e.g. 100m), detailed elevations of structures crossing or in the channel with their associated channel profiles, a long section showing both bank levels, hard and soft bed levels, water level and structure details and digital data in one or more river modelling formats, e.g. EACSD, Hec-Ras, ISIS and MIKE11. See a typical cross section here

Flow control, flood storage and gauging structure surveys – a detailed record of the exact layout and levels of structures is essential to enable accurate measurement of flow data, storage volumes and trigger levels.

Threshold level surveys – the collection of accurate level data using a digital level for properties in areas that may be at risk of flooding

Fluvial structure monitoring will normally be done by establishing stable off site monitoring datums and attaching monitoring targets to the structure that will move with it – these are then measured at intervals set according to the expected movement and the criticality of the structure.

Flood risk assessment surveys – we can provide a detailed level or topographic survey for any site with levels which will be acceptable to the Environment Agency and other public bodies.

Coastal Surveying

EDI Surveys has been involved with the Environment Agency’s coastal monitoring programme since 1991 and we are currently the holders of a 5 year contract to survey profile and grid surveys on the foreshore from Grimsby to Southend-on-Sea, approximately 400km of coastline.

The majority of the work involves the survey of level profiles along fixed transect lines from low water level to a point inland of the sea defence / cliff top or dune line, with these transects being spaced at intervals between 100m and 500m.

Using RTK GNSS survey units we take recordings of the locations position, height and ground covering type (i.e. grass, mud, sand etc) every few paces. Once back in the office the collected data is processed by software to create cross sections of the coast line. When this new data is laid over cross sections of the same coast line collected from previous years we can see a graphical representation of how our coastline is changing over time. This valuable information gives the Environment Agency data to create the defence polices needed to protect us from the risk of flooding and erosion.

Watercourse Surveys

We carry out a large number of watercourse surveys each year for the purposes of flood modelling and siltation assessment. Our main client for these projects is the Environment Agency but we also work for a number of consulting engineers and flood risk assessors. The surveys might be of anything from a dry ditch to the river Thames.

A recent project was the River Fynn here in Suffolk, a 12km long section of the watercourse from the village of Witnesham to the tidal Martlesham Creek on the river Deben. The survey requirement was to produce profiles of the watercourse at 100m intervals, profiles of all structures, a long section and digital data in ISIS and EACSD formats.

Topographic Survey – The Cornhill, Ipswich

Description: Our brief was to survey the Cornhill, the current market place in Ipswich and the focal point of the town center, prior to a proposed regeneration of the area.

Survey type: Topographical survey of the square with special emphasis on the position and level of the surround building footprints.

Survey equipment: Leica reflectorless total station theodolite and Leica GNSS with Smartnet network RTK in order to provide control to Ordnance Survey national grid and level datum.

Completion time: 1 week.

COAST

RIVER

Equipment

Leica DNA03 Level