scope:

This standard gives in addition to the NEN 3650 series safety requirements for pipelines on land and located in or nearby important public works. In 6.5 of NEN 3650-1:2020 the relationship between this standard and the NEN 3650 series is laid down. Figure 1 of NEN 3650-1:2020 shows the relationship in schematic form.

The standard applies irrespective of the fluid for all types of new pipeline to be installed (steel, concrete, plastic and cast iron).

Important public works are:

- a primary flood defence;

- a flood storage basin;

- a secondary flood defence;

- a primary road;

- a secondary road;

- a national or provincial canal for shipping.

NOTE 1 This name of the important public works is used in all the previous versions of NEN 3651 in accordance with the basic source of this standard: the "Pijpleidingcode" (Pipeline code) of South Holland [2].

The name of the important public works is not in line with the statutory name according to the "Waterwet" (Water Act) (January 2017). The existing name is maintained in the standard for editorial reasons.

Table 1 gives the names and the statutory names and hence the link with respect to safety requirements to be used.

NOTE 2 The safety standard for failure of the primary flood defences is determined for each dyke section ("dijktraject") in the "Waterwet" (Water Act). A dyke section is a part of a primary flood defence which has been standardized separately. A lower limit value (annual probability of flooding for which the dyke section shall have been designed as a minimum) and a signalling value (the annual probability of flooding which, if exceeded, is reported to the Minister of Infrastructure and the Environment) have been established for every individual dyke section. The lower limit standard varies between 1:100 and 1:1 000 000 and the signalling standard varies between 1:300 and 1:1 000 000.

NOTE 3 The probability of flooding is defined in the "Waterwet" (Water Act) as the probability of a dyke section losing its water-retaining capacity as a result of which the area protected by the dyke section will flood to such an extent that this will lead to fatalities or substantial economic loss.

NOTE 4 Regional flood defences are non-primary flood defences and are included in the label/certification of the "waterschap" (district water board) and/or indicated on the basis of a "provinciale verordening" (provincial regulation). These include not only "wet" but also "dry" flood defences. The regional flood defences are subdivided in Table 1 according to [24].

The topographical area in which the standard applies, is determined by the important public work and adjacent zones (safety zone).