The French State may prescribe an archaeological evaluation ahead of any public or private development project to ascertain whether the land in question contains any traces of human occupation. This intervention, which is undertaken by Inrap or an accredited local public authority service, conforms to a highly-structured process.

Updated on
05 June 2017

The regional prefect and his or her archaeological service may order an archaeological evaluation to be carried out prior to any major development scheme (such as a high-speed railway line, motorway or quarry) or when planning permission is filed (for a car park, for instance, or a block of flats).

The aim of this evaluation is to ascertain whether the land contains any traces of earlier human occupation that are likely to be destroyed by the planned work. Inrap or an accredited local authority service performs a survey on 5% to 10% of the land affected by the project.

The methodology makes it possible to detect, characterise, plot and date any archaeological deposits in the subsoil. In practice, fewer than 8% of development projects are subject to an archaeological evaluation every year.

Following this on-site intervention, the archaeologists submit an evaluation report to the State services (DRAC / the relevant Regional Archaeology Service). Based on these findings, either the developer is authorised to begin work immediately or a preliminary excavation is prescribed.

Aim of the evaluation

When land is developed for public or private purposes (to construct a road, for example, or a block of flats), it is inevitable that the ground will be disturbed.

Long before the building work begins, and to avoid work being interrupted in the event of a fortuitous discovery, an attempt is made to find out whether the land contains any traces of earlier human occupation: this is the archaeological evaluation. The process is designed to detect, characterise, plot and date any archaeological deposits by trenching 5% to 10% of the project’s surface area with a hydraulic digger.

State prescription

Ahead of any major development work (such as a high-speed train line, motorway or quarry) or when planning permission is filed, the regional prefect and his or her archaeological service may decide that an archaeological evaluation is required. In this event, Inrap or the public services accredited by the State suggest an “operational project” (with the relevant human and technical resources — and methodology — based on the scientific prescription), which will be used to assess the land’s archaeological potential.

An agreement is then signed between Inrap and the public or private developer. This sets the deadlines and conditions for carrying out the evaluation and, if necessary, the technical resources that will be financed by the developer.

Preparing the field evaluation

Inrap collects all the relevant information from the developer about the proposed development (the topography of the site plus the contact details of the other operators); decides on the composition of the archaeological team; and organises the necessary technical equipment (hydraulic diggers and site huts).

From a scientific perspective, the Regional Archaeology Service (DRAC) provides the Inrap operations manager appointed by the State with all the information concerning the deposits already discovered in the area (by consulting the national archaeological map).

The field evaluation

The evaluation in most cases consists in opening trenches at regular intervals to determine whether there are any deposits. The size of the trenches varies depending on the terrain: as a general rule, they range from 1.3 m to 3 m wide (equal to the width of the bucket of the digger) and are of variable length. When deposits are uncovered, it is sometimes useful to slightly enlarge the trenches — known as “windows” — to ensure a better understanding of their topology (post holes forming a building, for example). The depth of the excavations depends on the level at which the deposits are buried: from 30 cm below the current surface level to over 4 m, particularly for the earliest periods.

Trenches are dug as follows: an archaeologist, stationed in front of the bucket of the digger, guides the driver so that he or she can strip the soil horizontally until the deposits are reached. To this end, the archaeologist identifies abnormalities in the terrain (changes in colour and texture) that may signal the foundations of walls, rubbish pits, burial pits, etc. The archaeologist positions all these anomalies on a plan in order to plot the human occupation on the ground. Several different periods may be represented.

Some of the deposits are partially excavated, and the objects are collected and analysed so that the human occupation to which they are linked can be dated.

Evaluation report

Following the evaluation, a report is submitted to the State departments (DRAC / relevant Regional Archaeology Service).

Four different scenarios are then possible:

The evaluation is “negative”: the State allows the developer to start work.

The evaluation is “positive” but the State considers that the archaeological deposits are poorly preserved or do not have any genuine scientific interest, in which case the developer is authorised to start work.

The evaluation is “positive”: deposits are discovered on all or part of the project footprint. If the State considers that they are of sufficient scientific interest and in a good enough state of conservation, it may decide to carry out an archaeological excavation or modify the development project.

The evaluation reveals the presence of exceptional deposits that must be preserved in situ: the State asks the developer to integrate the deposits into its development project. This scenario is extremely rare.