Decree No. 79 / 2018 Coll.
Decree on the manner and extent of processing of the design and setting of flood areas and their documentation
Valid
Effective from 01.06.2018
79
DECLARATION
of 30 April 2018
on the manner and extent of processing of the design and setting of flood areas and their documentation
According to Section 66 (3) of Act No. 254 / 2001 Coll., on Water and on the Amendment of Certain Laws (Water Act), as amended by Act No. 150 / 2010 Coll.:
Subject matter
This decree sets out the manner and extent of processing of the flood area design by the watercourse manager and the manner and extent of determination of that flood area and its documentation by the water authority.
Basic concepts
For the purposes of this decree:
(a) flood line means the intersection of the water level with the earth's surface or the construction of a flood-proof waterworks during flooding;
(b) the period of repetition of floods 5, 20, 100 and 500 years shall mean the occurrence of floods that are reached or exceeded on average once every 5, 20, 100 and 500 years;
(c) flooded territory of the highest recorded natural flood means a territory which is defined by a flood line corresponding to the highest historically recorded and documented water level in the natural flood;
(d) inundation territory shall mean a territory which is flooded at flows exceeding the capacity of the watercourse;
(e) flood risk means an assessment of the flood intensity defined by the depth and rate of water flow at floods with different periods of repetition. Threatening takes high, medium, low and residual values.
Method and scope of processing of flood area design
The water flow manager shall consult the relevant water authority on the design of the flood area when starting work.
Documentation for the processing of flood area design
(1) The documentation for the processing of the flood area design includes:
(a) the standard hydrological data provided by the Czech hydrometeorological institutes (1);
(b) the handling order of the water works used to inhale or accumulate water which may significantly affect the flow rate during the passage of the natural flood in the solved section of the water flow, or the handling order of the water works system;
(c) the basic map of the Czech Republic in the scale 1: 10 0002) and the basic basis of the geographical data of the Czech Republic in the scale 1: 5 0002), if requested by the Water Authority,
(d) a digital terrain model or a digital relief model;
(e) an orthophotomap;
(f) the results of the geodetic orientation of the watercourse and the inundation area, including the objects affecting the flow;
(g) available data on natural floods recorded, including the highest natural flooding recorded; and
(h) detailed field survey to determine the roughness coefficient.
(2) The basic map of the Czech Republic on the scale of 1: 10 000 serves as a basis for encapsulating the flood area, its active zone with all its features and for creating flood hazard maps and flood threat maps.
Scope of processing of the flood area design
(1) The proposal for a flood area shall be processed for an inundation area designated by the watercourse manager or an appropriate sub-basin plan. The flood area is defined by a flood line with a period of repeated flooding of 100 years. The extent of the area covered corresponds to the hydraulic conditions of the continuous section of the water flow, the inundation area and takes into account the specified flood area.
(2) The elevation of the levels in the flood for whose standard hydrological characteristics the design of the flood line is processed shall be determined by a hydraulic calculation of uneven flow.
(3) When calculating the flood line, account shall be taken of the influence of the water flow of a higher order into which the water flow, for which the flood line proposal is processed, flows.
(4) The flood area shall also include the area behind the flood barriers which are installed at flood risk or under flood protection under Section 75 (2) (g) of the Water Act. In the event that such flood barriers have only a complementary function of local security of passages, passages, passes and permeability set up in a fixed flood protection measure or in a construction other than flood protection, the territory behind these flood barriers is not included in the flood area.
(5) For the inundation territory of each section of the water stream, flood hazard maps shall be processed for floods with a time of repetition of 5, 20, 100 and 500 years showing the extent of the flooded area, depth and flow rate. The hydrological characteristics of natural floods corresponding to the relevant technical standard (1) are based on the processing of maps.
(6) The flood hazard maps are the basis for the processing of the flood hazard map as set out in Annex 1 to this Decree.
Processing of the proposal for an active zone of flood land
(1) The proposal for an active zone of flood land is based on documentation for the processing of the design of flood areas pursuant to Section 4, flood hazard maps and flood threat maps.
(2) The active flood zone includes areas
(a) its own watercourse in the width defined by the coastal lines;
(b) all related watercourses, derivatives or other channels and the orifice of the main flow inflows in a width determined by coastal lines;
(c) the area between the coastal lines and the line of construction of the waterworks to protect against flooding along the watercourse;
(d) further identified on the flood threat map as a high threat;
(e) further defined on the flood threat map as a medium threat in places where, at the same time for floods with a time of repetition of 5, 20 or 100 years, one of the following conditions is met:
1. the depth of water is greater than or equal to 1,5 m;
2. the result of the water flow velocity vector is greater than or equal to 1,5 m / s; or
3. the product of the water depth value and the result of the water velocity vector is greater than or equal to 0,75 m2 / s; and
(f) the elevated areas defined on the flood threat map as low and moderate threats within the individual areas defined under (a) to (e).
(3) The active zone of the flood area shall not include isolated areas of high and medium threat, as well as areas behind flood barriers which are installed at flood risk or under flood protection under Section 75 (2) (g) of the Water Act.
(4) In justified cases, for example, where the water flow flows through the valley and the inundation area is not chipped, small or spring sections of the watercourses may, after consultation with the Water Authority, be proposed an active flood zone as the area defined by the flood flood line with a period of repetition of 20 years.
Design of flood area
(1) The proposal for a flood area submitted by the water flow manager to the water authority includes:
(a) the standard hydrological data referred to in Article 4 (1) (a);
(b) calculation of the recorded flood line in vector form in accordance with § 4 (2) and § 5,
(c) a view of the proposed flood area and the proposed active zone of the flood area above the map material referred to in Article 4 (1) (c);
(d) a description of how the design of the flood area and the active zone of the flood area is to be processed, including a justification for changes in the extent of the proposed flood area in relation to the previously established;
(e) a table of data on the calculated elevation levels of the flood levels for which the proposal has been processed for floods with a time of repetition of 5, 20, 100 and 500 years, including the level data for significant transverse water flow objects; data on calculated altitudes in the flow trough axis shall be provided in the table; and
(f) a view of the area flooded with the highest natural flood recorded, provided that the documents available to create such a view are available.
(2) A proposal for a flood area is submitted by the water flow manager to the water authority in paper and electronic form for making available to the municipalities and authorities concerned. It shall forward two copies in paper form to the Water Authority.
Method and extent of setting of flood land
(1) The Water Authority provides for a flood area for a continuous section of water flow pursuant to § 5 (1).
(2) Measures of a general nature fixing or changing the flood area shall always include:
(a) an extract of the cadastral territories concerned;
(b) the name of the watercourse and the determination of the watercourse section for whose inundation territory the flood area is established; and
(c) the basic data on the design of the flood area on the basis of which the flood area has been established and defined in its active zone and the basic data on its availability, the information on the designated flood area for which general measures have been modified or, where appropriate, cancelled.
(3) If the proposal for a flood area is not processed in accordance with this Decree, the Water Authority shall return it to the Water Water Manager for replenishment or change.
(4) The Water Authority shall send a measure of a general nature setting out, amending or revoking the flood area, to the Ministry of the Environment and to the procuring entities of Territorial Analysis with an indication of its effectiveness and appropriate documentation in electronic form. A copy of the documentation shall be transmitted by the water flow manager, indicating the receipt of efficacy in paper form.
Method and extent of documentation management
The documentation of the flood area shall be processed and stored in electronic form and in paper form in accordance with Annex 2 to this Decree.
Transitional provision
The provisions of Decree No. 236 / 2002 Coll.
Repeal
Decree No. 236 / 2002 Coll., on the method and extent of processing of design and setting of flood areas, is repealed.
Efficacy
This Decision shall enter into force on 1 June 2018.
Minister:
Mgr. Brabec v. r.
Příloha č. 1
Annex No 1 to Decree No 79 / 2018 Coll.
Procedure for calculating flood risk
1. Calculation of flood intensity
The flood intensity (IP) is understood as a measure of flood destruction and is defined as a function of water depth h [m] and water speed in [m / s]. The flood intensity is determined according to the following relationships:
IP = 0 h = 0 mh h > 0 m, v ≤ 1 m / sh. v h > 0 m, v > 1 m / s. 1
The input data for the calculation of flood intensity are the depth and water speed values for the given N-year flow rates in the inundation area (see Figure 1).
Figure 1 Schematic of the procedure of the risk matrix method for flood with a given period of repetition
The IP is calculated for all periods of repetition (for 5, 20, 100 and 500 years). The calculation results in raster data in which each grid cell contains data on the intensity of the IP flood for each repetition time.
If 1D models are used, where the field is represented only by transverse speed values in individual transverse profiles or sub-sections, an expert estimate of the distribution of speeds greater than 1 m / s in the flood area shall be made. If the water speed reaches lower values, it is not considered in the calculation of flood intensity.
2. Determination of flood threat
Flood threat Ri for the ith flood scenario corresponding to the culmination flow with the time of repetition Ni years with probability of crossing pi determine according to the relation:
Ri = 0,3 + 1,35.
where:
Pi = 1 - e1Ni, respectively Pi-1Ni for approximately N ≥ 5.3
The risk to Ri expressed in relation 2 for the ith flood scenario is shown in Table 1.
Determination of the threat level Ri is based on the IP flood intensity values for each repetition time (Table 1). A risk expressed in the range of 4 (high) to 1 (residual) should be identified for each IP flood intensity cell. The threshold values for each risk category are set out in Table 2. This procedure (Figure 1) should be repeated for all periods of repetition considered.
Table 2 Hazard classification R
In the next step an evaluation of the maximum risk value is carried out R for individual partial hazards Ri corresponding to the hazard scenarios (passage of the N- year culmination flow) according to the relationship:
Rx, y = maxi = 1n Ri, 4
where n indicates the number of flood risk scenarios evaluated (entering). The result is one raster layer containing maximum risk values R.
Tab. 1 Selected risk values R (according to relation 2) for the corresponding repetition times N and for the individual flood intensity values
3. Threat maps
The resulting maximum hazard values are displayed using the colour range (tab.2) in the Threat Map (Figure 2). The flood area is thus divided in terms of flood threat. This breakdown allows an assessment of the suitability of existing or future functional use of areas and recommendations to limit potential activities on areas in the flood area with a higher risk level (see Table 2).
Fig. 2 Example of threat map
Příloha č. 2
Annex No 2 to Decree No 79 / 2018 Coll.
Data standard documentation of flood area
The documentation shall consist of the following parts:
1. Measures of a general nature concerning the establishment of flood areas and the definition of its active zone;
2. Standard hydrological data,
3. The accompanying message,
4. Written longitudinal profile,
5. Calculation Profiles,
6. Flood lines, flood areas and its active zone,
7. Flood hazard maps,
8. Map of flood threat,
9. Map of flood area.
The formats below are mandatory, in addition to which parts of the documentation can be kept in other formats.
1. Measures of a general nature concerning the establishment of flood areas and the definition of its active zone
A document issued by the competent water authority.
Format: PDF document
2. Standard Hydrological Data
Document issued by the competent authorised institution (Czech hydrometeorological institute). The content of the document is the design flows Q5, Q20, Q100 and Q500 for the relevant water flow at the time of processing of the flood area design.
Format: PDF document
3. The accompanying message
A document prepared by the author of the flood area design and included in the submitted proposal to the Water Authority.
Format: PDF document
4. Written longitudinal profile
Tabular data describing the flow of levels and bottom in individual profiles.
Format: DBF, XML, XLS
| Databázová data | |||||
|---|---|---|---|---|---|
| Jméno atributu | Typ | Počet znaků | Počet des. míst | Popis atributu | Typ sloupce |
| TOK_ID | Číslo | 20 | 0 | ID toku dle Digitální báze vodohospodářských dat | Povinný |
| NAZ_TOK | Text | 60 | - | Název toku dle Digitální báze vodohospodářských dat | Povinný |
| IDVT | Číslo | 10 | 0 | ID toku dle Centrální evidence vodních toků | Povinný |
| ID_PROF | Text | 20 | - | Jednoznačný identifikátor profilu v rámci zpracovávané studie | Povinný |
| STAN | Číslo | 8 | 3 | Říční staničení profilu | Povinný |
| DNO | Číslo | 8 | 2 | Kóta dna profilu [m n. m.] | Povinný |
| LB | Číslo | 8 | 2 | Kóta levého břehu profilu [m n. m.] | Povinný |
| PB | Číslo | 8 | 2 | Kóta pravého břehu profilu [m n. m.] | Povinný |
| ZQn | Číslo | 8 | 2 | Kóta vypočtené hladiny v profilu pro Qn [m n. m.] | Povinný |
| Qn | Číslo | 8 | 2 | Návrhový průtok Qn [m3/s] | Povinný |
| POZN | Text | 254 | - | Charakteristika profilu (lávka, mostek, propustek apod.) | Povinný |
5. Calculating Profiles (not applicable to 2D models except significant cross objects)
GIS layer of calculated profiles used in the processed design.
| Geografická data | |||||
|---|---|---|---|---|---|
| Název - příklad | Profily_Sazava_rkm_70_75 (lze v poznámce doplnit slovním popisem - od mostu/profilu X1, Y1 k mostu/profilu X2, Y2) | ||||
| Formát | SHP (Esri) | ||||
| Geometrie | line, polyline | ||||
| Databázová data | |||||
| Jméno atributu | Typ | Počet znaků | Počet des. míst | Popis atributu | Typ sloupce |
| ID_PROF | Text | 20 | - | Jednoznačný identifikátor profilu v rámci zpracovávané studie | Povinný |
| TOK_ID | Číslo | 20 | 0 | ID toku dle Digitální báze vodohospodářských dat | Povinný |
| NAZ_TOK | Text | 60 | - | Název toku dle Digitální báze vodohospodářských dat | Povinný |
| IDVT | Číslo | 10 | 0 | ID toku dle Centrální evidence vodních toků | Povinný |
| TYP | Text | 20 | - | Typ profilu dle pořízení: 1. geodeticky zaměřený 2. TPE | Povinný |
| hl_q5 | Číslo | 6 | 2 | hladina v ose koryta při průtoku Q5 | Povinný |
| hl_q20 | Číslo | 6 | 2 | hladina v ose koryta při průtoku Q20 | Povinný |
| hl_q100 | Číslo | 6 | 2 | hladina v ose korytapři průtoku Q100 | Povinný |
| hl_q500 | Číslo | 6 | 2 | hladina v ose koryta při průtoku Q500 | Povinný |
| POZN | Text | 60 | - | Poznámka | Volitelný |
In addition to the above, it is possible to specify other attributes according to the needs of the water flow manager.
6. Flood lines, flood areas and its active zone
GIS layers of flood lines, established flood area and its active zone processed as a closed polygon for flooding with a time of repetition of 5, 20, 100 and 500 years. Each flood line and defined active zone will have a separate file containing just one relevant polygon, the repetition time will be part of the file name (e.g. Q5 _ Sazava _ rkm _ 70 _ 75).
| Geografická data | |||||
|---|---|---|---|---|---|
| Název - příklad | zu_Q5_Sazava_rkm_70_75 (lze v poznámce doplnit slovním popisem - od mostu/profilu X1, Y1 k mostu/profilu X2, Y2) | ||||
| Formát | SHP (Esri) | ||||
| Geometrie | Polygon | ||||
| Databázová data | |||||
| Jméno atributu | Typ | Počet znaků | Počet des. míst | Popis atributu | Typ sloupce |
| TOK_ID | Číslo | 20 | 0 | ID toku dle Digitální báze vodohospodářských dat | Povinný |
| NAZ_TOK | Text | 60 | - | Název toku dle Digitální báze vodohospodářských dat | Povinný |
| IDVT | Číslo | 10 | 0 | ID toku dle Centrální evidence vodních toků | Povinný |
| DAT_ZPRA | Text | 10 | Datum zpracování | Povinný | |
| MODEL | Text | 25 | Informace o použitém hydrodynamickém modelu | Povinný | |
| DMT | Text | 50 | Informace o použitém digitálním modelu terénu (zdroj, přesnost) | Povinný | |
| TOKREC_ID | Číslo | 20 | 0 | ID recipientu dle Digitální báze vodohospodářských dat | Volitelný |
| REC_NAZ | Text | 60 | - | Název recipientu dle Digitální báze vodohospodářských dat | Volitelný |
In addition to the above, it is possible to specify other attributes according to the needs of the water flow manager.
7. Characteristics of flood hazard map
GIS layers processed as a point layer / grid for all periods of repetition (5, 20, 100, 500 years). Each repetition time will have a separate set containing just one relevant point layer / grid. The name of the file will clearly define the characteristics of the flood (depth / speed), the size of the model used and the time of repetition (e.g. HQ5 _ Sazava _ rkm _ 70 _ 75 / RQ5 _ Sazava _ rkm _ 70 _ 75).
Speed 1D model
| Geografická data | |||||
|---|---|---|---|---|---|
| Název - příklad | RQ5_1D_Sazava_rkm_70_75 | ||||
| Formát | SHP (Esri) | ||||
| Geometrie | Point | ||||
| Databázová data | |||||
| Jméno atributu | Typ | Počet znaků | Počet des. míst | Popis atributu | Typ sloupce |
| TOK_ID | Číslo | 20 | 0 | ID toku dle Digitální báze vodohospodářských dat | Povinný |
| NAZ_TOK | Text | 60 | - | Název toku dle Digitální báze vodohospodářských dat | Povinný |
| IDVT | Číslo | 10 | 0 | ID toku dle Centrální evidence vodních toků | Povinný |
| ID_PROF | Text | 20 | - | Jednoznačný identifikátor profilu v rámci zpracovávané studie | Povinný |
| RYCHLOST | Číslo | 3 | 1 | Průměrná rychlost proudění v profilu | Povinný |
Speed 2D model
| Geografická data | |||||
|---|---|---|---|---|---|
| Název - příklad | RQ5_2D_Sazava_rkm_70_75 | ||||
| Formát | TIFF georeferencovaný | ||||
| Geometrie | Rastr | ||||
| Hodnota buňky | Typ | Počet znaků | Počet des. míst | Popis | Typ sloupce |
| Rychlost | Číslo | 4 | 2 | Rychlost proudění | Povinný |
Depth
| Geografická data | |||||
|---|---|---|---|---|---|
| Název - příklad | HQ5_1D_Sazava_rkm_70_75 (HQ5_2D_Sazava_rkm_70_75) | ||||
| Formát | TIFF georeferencovaný | ||||
| Geometrie | Rastr | ||||
| Hodnota buňky | Typ | Počet znaků | Počet des. míst | Popis | Typ sloupce |
| Hloubka | Číslo | 4 | 2 | Vypočtená hloubka vody | Povinný |
8. Flood threat
| Geografická data | ||||||
|---|---|---|---|---|---|---|
| Název - příklad | Ohrozeni_Sazava_rkm_70_75 | |||||
| Formát | SHP (Esri) | |||||
| Geometrie | Polygon | |||||
| Databázová data | ||||||
| Jméno atributu | Typ | Počet znaků | Počet des. míst | Popis atributu | Typ sloupce | |
| TOK_ID | Číslo | 20 | 0 | ID toku dle Digitální báze vodohospodářských dat | Povinný | |
| NAZ_TOK | Text | 60 | - | Název toku dle Digitální báze vodohospodářských dat | Povinný | |
| IDVT | Číslo | 10 | 0 | ID toku dle Centrální evidence vodních toků | Povinný | |
| KAT_OHR | Číslo | 1 | 0 | Kategorie ohrožení (1 - zbytkové, 2 - nízké, 3 - střední, 4 - vysoké) | Povinný | |
9. Map of flood lines, flood area and active zone
Individual map elements are displayed according to the following rules:
Flood lines
| Doba opakování (roky) | RGB | CMYK (kód barvy) | Čerchování (čára-mezera) [body] | Síla čáry [body] |
|---|---|---|---|---|
| 5 | 82 / 174 / 50 | 70 / 0 / 100 / 0 | 2-1 | 0,5 |
| 20 | 0 / 130 / 81 | 100 / 0 / 80 / 20 | 4-1 | 0,75 |
| 100 | 0 / 100 / 163 | 100 / 40 / 0 / 20 | plná | 1 |
| 500 | 82 / 33 / 122 | 80 / 100 / 0 / 10 | 6-1-1-1 | 1,5 |
Filling of polygons defined by flood lines
| Doba opakování (roky) | RGB (kód barvy, krytí) | CMYK (kód barvy, krytí) |
|---|---|---|
| 5 | 24 / 114 / 120 70 % | 80 / 25 / 40 / 30 70 % |
| 20 | 66 / 179 / 142 60 % | 70 / 0 / 55 / 0 60 % |
| 100 | 180 / 205 / 37 60 % | 38 / 0 / 95 / 0 60 % |
| 500 | 253 / 235 / 54 30 % | 0 / 5 / 100 / 0 30 % |
Active zone - cross-cut shrafur (orientation of the shraf 0 ° and 90 °, width of the shraf 10 points, thickness of the shraff 0,5b), force of the outline line 2b, preferentially inside (the force of the line is drawn from the edge of the area inwards), colour (RGB: 230 / 0 / 0, CMYK: 10 / 100 / 100 / 0), cover 75%.
Base map 1: 10 000 in grey shades, cover 40%, if necessary on a larger scale (1: 5 000)
Format: PDF document
1) ČSN 75 14 00 Hydrological data of surface water.
2) Government Decree No. 430 / 2006 Coll., on the establishment of geodetic reference systems and national map works binding on the territory of the State and the principles of their application, as amended by Government Decree No. 81 / 2011 Coll.
3) § 3a (d) of Act No 359 / 1992 Coll., on the Geographic and Catastral Authorities, as amended.
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Regulation Information
| Citation | Decree No. 79 / 2018 Coll., on the method and extent of processing and setting of flood areas and their documentation |
|---|---|
| Regulation Type | - |
| Author | - |
| Collection | Code of Laws |
| Date of Promulgation | 18.05.2018 |
|---|---|
| Effective from | 01.06.2018 |
| Effective until | - |
| Status | Valid |
The regulation text is for informational purposes only.
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