Russian legislation has tightened construction rules in underflooded and flooded areas. This does not impose a complete ban on construction, but it requires to meet certain requirements.
Construction in underflooded and flooded areas.
The procedure for establishing flooding and underflooding areas is determined by the Decree of the Government of the Russian Federation of April 18, 2014 No. 360.
According to the document, the boundaries of the underflooding and flooding areas are established by the territorial authorities of the Federal Agency for Water Resources, and the data on these sites are entered into the Unified State Register of Real Estate. It is possible to change the status of the territory only after the disappearance of the danger – the termination of the existence of the water body.
The Water Code of the Russian Federation (Article 67.1) prohibits capital construction without providing engineering protection within the boundaries of flooding and underflooding areas.
In turn, protective measures are given in the Code of Practice «Engineering protection of the territory against flooding and underflooding” (SP 104.13330.2016).
Terms and Definitions
Flooding is the coverage of an area with water as a result of its level increase in a pond.
Underflooding is a critical increase of the groundwater level with negative consequences.
Engineering protection of the territory from underflooding and flooding is a set of measures and constructions aimed at preventing hazardous processes or eliminating their negative consequences.
Necessity of the project of engineering protection against underflooding and flooding
Engineering protection projects are developed both for designed buildings and consructions and for existing facilities. These can be separate buildings, enterprises, settlements, infrastructure facilities (roads and railways, engineering networks), etc.
Implementation of engineering protection measures (in some cases, the availability of design documentation) is required to obtain a construction permit in the underflooded or flooded area, as well as to put into operation the constructed facilities.
The main methods of engineering protection of territories from underflooding and flooding:
– artificial increase of the surface of the territory to flood-free planning marks (for example, the creation of an embankment under the protected constructions);
– diking of the territory – the creation of dams, embankments or other enclosing constructions that prevent the spread of water;
– creation of constructions for river-bed regulating and constructions for regulating and derivation surface run-off
– creation of systematic drainage systems and local drainages for water derivation (including other measures for water decrease);
– installation of grout curtains and impervious screen
– protection of water-bearing engineering communications (in case of man-caused risks)
The assistive aids of engineering protection include the use of the natural properties of natural systems:
– clearing river-beds and former river-beds to improve the efficiency of water derivation
– planting hygrophyte trees to improve drainage
Protection methods are selected based on the specifics of the protected area, the type of hazardous phenomenon, on the basis of a technical and economic comparison of options.
When designing measures for engineering protection against underflooding and flooding, the designers take into account the associated risks of the development of hazardous geological processes (landslides, karst and suffosion, destruction of coasts, etc.), the presence of soft and specific soils, as well as the risks associated with seismic activity.
“GEOIZOL project” performs both complex design of measures for engineering protection of territories, and provides individual design services.
Engineering protection design cost
Engineering protection measures are quite costly. Their cost can reach tens and even hundreds of millions of rubles. At the same time, the share of design is about 5-10% of the cost of construction and installation work.
Cost of design and construction tend to be too high for private customers who need to protect a single household.
“GEOIZOL project” is mainly deal with medium and large objects. For example, when protection from underflooding and flooding must be performed for a village or enterprise, or the length of the coastline exceeds 500 meters. However, each case is considered separately.
Required data for engineering protection design
To select the optimal technical solution and the subsequent development of an engineering protection project, the following initial data are required:
– topographic surveying and / or topographic plan of the protected area;
– general plan or layout of protected objects;
– results of geotechnical and hydrometeorological surveys;
– results of long-term observations of the regime of surface and ground waters.
During the analysis of the initial data, the sufficiency of the provided or the need for additional information is determined.
Engineering protection design procedure
The implementation of an integrated design of engineering protection against underflooding and flooding can be divided into the following stages:
– analysis of initial data;
– conducting additional inspections and surveys, going to the facility (if necessary);
– development of a design assignment;
– development and approval of the concept of engineering protection (with the choice of the best variant);
– design (development of a specialized section in project documentation or preparation of an Explanatory Note)
– approval with the examination authorities (if necessary);
– architectural supervision during the construction and installation works.