The world of water supply and sanitation. Calculation of wastewater Calculation of the amount of rain and melt water

Storm drainage is one of the critical systems equipment for a residential area, which, unfortunately, many owners simply forget about or take it too lightly. And it is completely in vain - hopes that rain or melt water will go away by itself often lead to gradual waterlogging of the territory, destruction or failure of laid paths and platforms, erosion and erosion of the foundation structures of erected buildings, waterlogging of their walls and other negative consequences.

Storm sewerage includes many different elements that are responsible for a specific water collection area, for several such areas, or for the entire system as a whole - these are stormwater inlets, pipes, wells, and collectors. In order for them to be able to cope with their task, their parameters must correspond to the expected volumes of water. And when planning the system, the calculator for calculating the volume of storm drains, which is offered to the reader, may be useful.

Below, under the calculator, a brief explanation of how it works will be given.

MINISTRY OF CONSTRUCTION AND HOUSING AND COMMUNAL SERVICES OF THE RUSSIAN FEDERATION

ORDER

In accordance with paragraph 25 of the Rules for organizing commercial accounting of water and wastewater, approved by Decree of the Government of the Russian Federation dated September 4, 2013 N 776 (Collection of Legislation Russian Federation, 2013, N 37, art. 4696; 2014, N 14, Art. 1627), subclause 5.2.73 of clause 5 of the Regulations on the Ministry of Construction and Housing and Communal Services of the Russian Federation, approved by Decree of the Government of the Russian Federation of November 18, 2013 N 1038 (Collection of Legislation of the Russian Federation, 2013, N 47 , art. 6117, 2014, N 12, art. 1296),

I order:

1. Approve the attached Guidelines for calculating the volume of accepted (allocated) surface waste water.

2. Control over the implementation of this order shall be entrusted to the Deputy Minister of Construction and Housing and Communal Services of the Russian Federation A.V. Chibis.

Minister
M.A. Men

Registered
at the Ministry of Justice
Russian Federation
February 24, 2015,
registration N 36194

Guidelines for calculating the volume of accepted (discharged) surface wastewater

APPROVED
by order
Ministry of Construction
and housing and communal services
Russian Federation
dated October 17, 2014 N 639/pr

I. General provisions

1. These Guidelines for calculating the volumes of accepted (discharged) surface wastewater (hereinafter referred to as the Guidelines) determine the procedure for commercial accounting of surface wastewater (hereinafter also referred to as runoff) accepted (discharged) into the centralized drainage system.

2. These Guidelines do not cover cases of water entering centralized systems drainage during rising water levels (floods) in water bodies near which centralized drainage systems are located; water used for washing and disinfecting networks after liquidation of accidents; water from leaks from water supply and heating networks; water entering the centralized drainage system from snow melting points as a result of forced snow melting carried out at such points.

II. Features of the receipt and calculation of atmospheric precipitation volumes

3. Atmospheric precipitation:

- discharged into centralized drainage systems in the form of rain, melted water, infiltration water (ground (underground) water entering centralized drainage systems in the absence of drainage connections, through leaks, leaky connections of elements, cracks and holes formed during the operation of existing sewer networks , and during the construction of new networks), as well as drainage water (ground (underground) water entering centralized drainage systems when drainage is connected to them);

- are consumed in the form of moisture for evapotranspiration (total moisture consumption for transpiration (evaporation of water by a plant) and evaporation (evaporation from the soil surface);

- enter unorganized water bodies and lower horizons groundwater.

4. The amount of precipitation (daily, monthly, seasonal and annual layers), information on temperature, air humidity are determined based on information received from Federal service on hydrometeorology and monitoring environment, including in the form of data from the Unified State Data Fund on the state of the environment, its pollution, other organizations licensed to carry out activities in the field of hydrometeorology and related areas (including average monthly data for the last 3 years), or in accordance with building climatology standards. If there is a discrepancy between the data obtained from the above sources, the data obtained from the Unified State Data Fund on the state of the environment and its pollution are used.

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5. When determining the volume of rainwater wastewater, the amount of precipitation falling during the warm period of the year (from April to October) is taken into account; when determining the volume of melt runoff, the amount of precipitation falling during the cold period of the year (from November to March) is taken into account.

6. If it is necessary to determine the forecast volumes of surface runoff (to determine the price of a sewerage contract, formulate an income plan, balance calculations of water disposal), it is recommended to take a layer of atmospheric precipitation (the amount of precipitation per calendar month or other period of time, expressed as a layer (in mm ), uniformly distributed over the area), corresponding to the annual layer of 20% supply (the probability of the occurrence of a phase-uniform runoff value equal to or greater than a given value):

N os = Nose *K, (m/year, m/month),

K is a coefficient that takes into account the ratio of the annual amount of precipitation of 20% of the probability to the average annual amount of precipitation. K =1.07.

Nos - the average annual amount of atmospheric precipitation, determined from information received from the Federal Service for Hydrometeorology and Environmental Monitoring, including in the form of data from the Unified State Data Fund on the state of the environment, its pollution, and other organizations licensed to operate in the field of hydrometeorology and related fields (including average monthly data for the last 3 years), or in accordance with standards for building climatology.

________________

Section II of the Administrative Regulations for execution by the Federal Service for Hydrometeorology and Environmental Monitoring state function to ensure the functioning of hydrometeorological observation points and a system for receiving, collecting and distributing hydrometeorological information on the territory of the Russian Federation, approved by order of the Ministry of Natural Resources and Ecology of the Russian Federation dated October 31, 2008 N 299 (Bulletin of regulatory acts of federal executive authorities, N 7, February 16 2009, registered with the Ministry of Justice of the Russian Federation on December 17, 2008, registration N 12879).

Order of the Federal Service for Hydrometeorology and Environmental Monitoring dated April 24, 2008 N 144 “On approval of the Administrative Regulations of the Federal Service for Hydrometeorology and Environmental Monitoring for the execution of the state function “Maintaining the Unified State Data Fund on the state of the environment, its pollution” (Bulletin of regulatory acts of federal executive authorities, No. 38, September 22, 2008, registered with the Ministry of Justice of the Russian Federation on May 23, 2008, registration No. 11742).

7. In the absence of data on the layer of actual precipitation for a specific locality, as well as in the case of the presence of several observation posts of the state observation network (or departmental observation network designed to determine the actual amount of precipitation in one locality), data on the actual precipitation precipitation data are received from the observation network post closest to the center of the populated area. Data on actual precipitation can be taken as a single value for the entire populated area or determined for each specific land plot(territory) by linking him (her) to the nearest observation network post.

8. Water supply and sewerage organizations operating centralized sewerage systems, in settlements with subscribers when determining the volume of surface runoff for a calendar month, use information on the actual layer of precipitation received from the Federal Service for Hydrometeorology and Environmental Monitoring, including in the form data from the Unified State Data Fund on the state of the environment, its pollution, other organizations licensed to carry out activities in the field of hydrometeorology and related fields (including average monthly data for the last 3 years), or data from standards for building climatology .

________________

Section II of the Administrative Regulations for the execution by the Federal Service for Hydrometeorology and Environmental Monitoring of the state function of ensuring the functioning of hydrometeorological observation points and a system for receiving, collecting and distributing hydrometeorological information on the territory of the Russian Federation, approved by order of the Ministry of Natural Resources and Ecology of the Russian Federation dated October 31, 2008 N 299 (Bulletin of normative acts of federal executive authorities, No. 7, February 16, 2009, registered with the Ministry of Justice of the Russian Federation on December 17, 2008, registration No. 12879).

Order of the Federal Service for Hydrometeorology and Environmental Monitoring dated April 24, 2008 N 144 “On approval of the Administrative Regulations of the Federal Service for Hydrometeorology and Environmental Monitoring for the execution of the state function “Maintaining the Unified State Data Fund on the state of the environment, its pollution” (Bulletin of regulatory acts of federal executive authorities, No. 38, September 22, 2008, registered with the Ministry of Justice of the Russian Federation on May 23, 2008, registration No. 11742).

9. For water supply and sewerage organizations operating only centralized storm drainage systems, when making payments to subscribers, the volume of surface runoff for a calendar month can be calculated based on the average annual precipitation as 1/12 of the average annual volume of surface runoff.

10. From the drainage area of land plots (territories) adjacent to water bodies that are not included in the zone of centralized drainage of surface wastewater (an area determined taking into account the location of stormwater intake structures, sewer networks and the terrain from which surface wastewater is discharged into the centralized system drainage), an area of 50 meters wide along the coastline land plot (territory), since surface runoff from this surface does not enter centralized drainage systems.

11. If there are on-site sewerage networks, the entire territory used by the subscriber is recognized as being located in the zone of centralized drainage of surface wastewater.

12. In the absence of approved zones for centralized drainage of surface wastewater, defined in the water supply and sanitation scheme, the area of land plots (territories) of subscribers, the surface runoff from which unorganizedly flows into centralized sewerage systems, can be determined taking into account the vertical layout of the sewerage territory (land area (territories), the possession, use or disposal of which is carried out by the subscriber, located in the zone of centralized drainage of surface wastewater, the surface runoff from which enters the centralized drainage system), subject to the provision of maps of land plots (territories) to scale to the water supply and sewerage organization M 1:500, carried out by an organization licensed for geodetic and cartographic work, indicating the boundaries, types of surfaces, drawing all water-carrying communications and marks on the groundwater level.

territory the shortest distance of 50 meters in both directions from the drainage system (sewer network).

III. Calculation of volumes of accepted (discharged) surface wastewater

14. Surface wastewater (W ps) accepted into centralized drainage systems includes rain, melt, ground (infiltration, drainage) and irrigation wastewater

W ps = W d + W t + W gr + W m, (m)

W d - volumes of rain runoff, (m)

W t - volumes of melt runoff, (m)

W gr - volumes of groundwater W gr = (W inf + W dr),

W inf - volumes of infiltration runoff, (m)

W dr - volumes of drainage flow, (m)

W m - volumes of irrigation runoff, (m)

15. Calculation of rainwater runoff volumes is carried out using the formulas:

Average annual volume of rainwater runoff:

W =10 * N * F * avg d, (m/month)

Monthly volume of rainwater runoff:

W = 10 * N * F * avg d, (m/month)

Actual annual volume of rainwater runoff:

W = W, (m/year)

Where:

W, W - average annual and actual annual volume of rainwater runoff, respectively,

H - average annual layer of atmospheric precipitation for the warm period of the year (April - October, rain layer), (mm),

H - layer of atmospheric precipitation for the months of the warm period (April - October, rain layer), (mm).

When determining the actual volume of rain runoff, the amount of precipitation layer is taken based on information received from the Federal Service for Hydrometeorology and Environmental Monitoring, including in the form of data from the Unified State Data Fund on the state of the environment, its pollution, and other licensed organizations to carry out activities in the field of hydrometeorology and related areas (including average monthly data for the last 3 years) or in accordance with standards for building climatology.

________________

F - the area of the land plot (territory) owned by the subscriber from which surface wastewater is discharged into the centralized drainage system, including unorganized discharge of surface wastewater (discharge of rain, melt and irrigation water into the centralized drainage system outside the territories of subscribers and other persons with their subsequent entry along the natural slope of the terrain into a centralized drainage system or into water body, including through the sewer territories of other subscribers), (ha);

avg - the weighted average value of the runoff coefficient (the ratio of the volume of surface runoff on the drainage surface to the total volume of precipitation that fell during the calculation period (per day, month, year) in a given territory) for areas with different types coatings;

avg = (Fi * i) /F, (calculation is made for territories with different types of surfaces),

Where:

F i, (ha) - the sum of areas with different types of surfaces. Data on the breakdown of the territory by type of surface are accepted on the basis of a subscriber’s certificate or according to inventory data.

i - rain runoff coefficient for various types surfaces is taken taking into account the permeability of the surface, including:

roofs and asphalt concrete pavements - 0.7;

paving stones and cobblestones - 0.5;

ground surfaces - 0.2;

lawns - 0.1.

16. The volume of melt runoff is calculated using the formulas:

Average annual volume of melt runoff

W = 10 * N * F * t * Ku, (m/year),

Monthly volume of melt runoff

W = 10 * N * F * t * Ku, (m/month),

Actual annual volume of melt runoff

W = W, (m/year),

Where:

W, W - average annual and actual annual volume of melt runoff, respectively;

H, (mm) - layer of atmospheric precipitation during the cold season (November - March, thawed layer);

H, (mm) - layer of atmospheric precipitation for the months of the cold period (November - March, thawed layer).

When determining the actual volume of melt runoff, the amount of precipitation layer is taken based on information received from the Federal Service for Hydrometeorology and Environmental Monitoring, including in the form of data from the Unified State Data Fund on the state of the environment, its pollution, and other licensed organizations to carry out activities in the field of hydrometeorology and related areas (including average monthly data for the last 3 years) or in accordance with standards for building climatology.

________________

17. Calculation of groundwater volumes is carried out as follows:

In the absence of results of actual measurements of drainage water inflow and initial data for calculating their flow rates and volumes, the total (total) volume of groundwater (drainage and infiltration) water entering the drainage system is determined.

W + W = Wg info.etc. (m).

Taking into account climatic (air temperature, amount of precipitation by month) and other conditions, the distribution of W dr by month may change. The monthly volume of drainage and infiltration waters can be taken according to the formula

The maximum daily volume of infiltration and drainage waters is taken as the daily average (in the corresponding month) with a coefficient = 1.1, taken according to Table No. 1.

Table No. 1.

Table No. 1

Calculation of the volumes of infiltration and drainage runoff (in the absence of data on the volume of drainage runoff) is carried out using the formula:

W info.etc. = 10 * N info.etc. * F, (m/year),

W info.etc. - annual volumes of infiltration and drainage flows entering centralized drainage systems;

F, (ha) - the area of the land plot (territory) owned by the subscriber from which surface wastewater is discharged into the centralized drainage system, including unorganized discharge of surface wastewater.

N info.etc. = Нoc - Notv - Nisp, - Notv. t.ub. (mm/year)

a) Ninf.etc. - annual layer discharged by a centralized drainage system in the form of drainage and infiltration water.

The H inf.dr values are calculated by season (warm, cold):

b) N os - the annual layer of atmospheric precipitation is accepted according to information received from the Federal Service for Hydrometeorology and Environmental Monitoring, including in the form of data from the Unified State Data Fund on the state of the environment, its pollution, and other organizations licensed to carry out activities in the field of hydrometeorology and related fields (including average monthly data for the last 3 years) or in accordance with standards for building climatology.

________________

N os = Nd + Nt, (mm/year).

Нд, (mm) - layer of atmospheric precipitation during the warm period of the year (from April to October).

Nt, (mm) - layer of atmospheric precipitation during the cold period of the year (from November to March).

c) N, - the volume of wastewater discharged by the centralized drainage system per year: N = N d + N t, (mm/year).

N d - the annual layer of drained rainwater is calculated by the formula: N d = 0.1 * W d/F, (mm/year).

N t - the annual layer of discharged melt runoff is calculated by the formula: N t = 0.1 * W t / F, (mm/year).

d) N isp, is the annual layer of atmospheric precipitation for evaporation (physical evaporation and transpiration), N isp = N isp + N isp (mm/year).

N isp, (mm/year) - layer of atmospheric precipitation for runoff evaporation (during the warm period), Nisp = N isp. * Ke * K tr, (mm).

N isp, (mm/year) - the layer of atmospheric precipitation for runoff evaporation (during the cold period), when calculating the layer of atmospheric precipitation spent on evaporation in the cold period, the shielding effect and transpiration coefficients are taken equal to 1, that is, the layer for evaporation is equal to evaporation (the maximum possible evaporation under given meteorological conditions from a sufficiently moistened underlying surface (at an arbitrarily high rate of water supply to the evaporating surface))

N use = Lower, (mm)

N used., (mm) - evaporation per unit of undeveloped surface, depends on climatic conditions(average monthly air temperature).

Average temperature values for the months of the year, data on evaporation values are taken based on information received from the Federal Service for Hydrometeorology and Environmental Monitoring, including in the form of data from the Unified State Data Fund on the state of the environment, its pollution, and other licensed organizations to carry out activities in the field of hydrometeorology and related areas (including according to average monthly data for the last 3 years), or in accordance with standards for construction climatology.

It is allowed to take monthly layers of evaporation according to the table. N 2.

Average values for temperatures not reflected in Table No. 2 are determined using interpolation and extrapolation.

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Table No. 2. "Dependence of the coefficient N of use on the average monthly air temperature"

Table No. 2


Months of the year	Monthly amounts of evaporation, mm at average monthly air temperature, °C

I-V (January - May)

VII-XII (July - December)

N use = (N use 1 + N use 2 + N use 3 + N use 11 + N use 12) - determined for the corresponding month,

N isp. 1 - evaporation for January,

N isp. 2 - evaporation for February,

N isp. 3 - evaporation for March,

N isp. 11 - evaporation for November,

N isp. 12 - evaporation rate for December.

N use = (N use 4 + N use 5 + N use 6 + N use 7 + N use 8 + N use 9 + N use 10) - determined for the corresponding month,

N isp. 4 - evaporation for April,

N isp. 5 - evaporation for May,

N isp. 6 - evaporation for June,

N isp. 7 - evaporation for July,

N isp. 8 - evaporation for August,

N isp. 9 - evaporation rate for September,

N isp. 10 - evaporation rate for October

Ke - the shielding effect coefficient (reflecting the degree of reduction in evaporation by moisture-impermeable coatings - asphalt, concrete and other coatings) depends on the building density (an indicator characterizing the intensity of use of territories).

The value of the correction factor Ke should be taken for the warm period.

Ke = 0.5 at high degree improvement (large and large cities);

Ke = 0.8 (medium and small cities).

K tr - Transpiration coefficient, taking into account the consumption of groundwater for transpiration by vegetation (applied for the warm period).

K tr = 1+(0.45 * (f))/((1-p)*F),

f - area occupied by trees and shrubs (data is accepted based on information from subscribers provided when concluding a drainage agreement);

p - building density (the value p can be taken for large and large cities = 0.65, for medium and small cities = 0.38).

F is the area of the land plot (territory).

e) N.T.ub., (mm) - annual layer, taking into account removal (removal of snow to snow melting points or specialized points for snow storage) during the cold period (from November to March).

N.T.ub.= Nt * (1 - Ku), (mm/year),

Ku - snow removal coefficient applies to subscribers whose subject of activity is cleaning urban areas of the road network with the removal of snow to snow melting points or specialized points for snow storage (Ku = 0.5),

Ku - snow removal coefficient applies to subscribers transporting snow to snow melting points or specialized snow storage points (Ku = 0.8).

If the sum (N + N) is greater than Nos or (Notv. + N isp) is greater than N oc, the volumes of infiltration and drainage runoff for the specified period are not calculated.

18. Calculation of drainage volumes (if data on connecting drainage networks to centralized drainage systems is available) is carried out using the formula:

Where:

T - number of days,

Q, (m/day) - average drainage flow rate,

N other - annual layer of drainage runoff, calculated by the formula:

N other = 0.1 * W d/ F, (mm/year).

Drainage flow can be determined:

1) by calculation (by filling the container and a stopwatch);

2) using a spillway equipped with a level gauge;

3) by measuring flow velocities and depths;

4) by measuring the depth of water flow at drops;

5) using devices for pumping drainage runoff with pumps.

The volume of drainage flow discharged into centralized drainage systems is calculated for the corresponding type of drainage network, based on average annual groundwater levels and filtration coefficients established according to technical (including design) and/or executive documentation.

In the absence of design and/or as-built documentation, the volume of drainage runoff (organized) diverted to centralized drainage systems is calculated using engineering-geological maps of the city (other populated area).

19. The volume of irrigation wastewater is calculated using the formula:

W m = 10 * m * k * m * F m, where:

W m, (m/year) - the volume of irrigation water entering centralized drainage systems;

m, (l/m) - specific water consumption for washing road surfaces, taken equal to 1.5 l/sq.m per wash;

k is the average number of washes per year, for middle zone Russian Federation is assumed to be equal to 150. Data is accepted based on certificates from specialized enterprises containing the road network, as well as based on data from concluded state and municipal contracts for the performance of relevant work or provision of services;

m = 0.5 - runoff coefficient for irrigation water;

F m, (m) - surface area subject to washing/watering.

Irrigation runoff is calculated during the warm period (from April to October).

20. If subscribers have technical (including design) and executive documentation for the drainage network, the type of drainage and the expected average annual volume of drainage flow are established, which is determined by calculation for the corresponding type of drainage based on the average annual groundwater levels and filtration coefficients established according to design or as-built documentation in accordance with the options given in these Guidelines.

In the absence of design and/or as-built documentation, the volume of drainage flow (organized) diverted to centralized sewerage systems is calculated using engineering-geological maps of the city (other populated area).

In the absence of data on the volumes of drainage runoff, the calculation of the volumes of surface runoff diverted to centralized drainage systems in the form of groundwater (infiltration, drainage) is made from the total area.

If data on the volumes of drainage runoff is available, the calculation of the volumes of surface runoff diverted to centralized drainage systems from infiltration runoff should be made from the total area of the territories, with the exception of territories not covered drainage system drainage.

Electronic document text
prepared by Kodeks JSC and verified against:
Official Internet portal
legal information
www.pravo.gov.ru, 02/27/2015,
N 0001201502270001

December 13 2017

Calculation of external rainwater drainage

Calculation example storm sewer(Moscow region, Noginsk district). The calculation was carried out according to SP 32.13330.2012.

surface	Area F, ha	% of total F	Coefficient	ψ d (mid)	Coefficient	ψ mid
asphalt concrete road surfaces	1,390	0,18	0,60	0,108	0,95	0,171
Roofing of buildings	0,770	0,10	0,60	0,060	0,95	0,094
gravel	0,480	0,06	0,45	0,027	0,30	0,018
Ground surfaces	5,110	0,66	0,100	0,066	0,10	0,066
Total	7,750	1		ψ d (mid) = 0.261		ψ mid =0.349

The average annual volume of surface wastewater W g is determined by:

W g = W d + W t + W m, (formula 4, clause 7.2.1, SP 32.13330.2012)

Where: W d, W t, W m – average annual volume of rain, melt and irrigation water, respectively, m 3

W d = 10h d Ψ d F=10*465*0.261*7.75=9,406.95 m3 (formula 5, clause 7.2.2, SP 32.13330.2012)

W t = 10h t Ψ t K y F=10*225*0.5*1*7.75=8,718.75 m 3 (formula 6, clause 7.2.2, SP 32.13330.2012)

W m = 10mkΨ m F m =10*0.5*150*0.5*7.75=521.25 m 3 (formula 7, clause 7.2.6, SP 32.13330.2012)

W g =9,406.95 +8,718.75 +521.25 =18,646.95 m 3

Where: F is the drainage area of the collector, ha;

K y - coefficient taking into account snow removal (see 7.3.5, SP 32.13330.2012), assumed in the calculation = 1;

h d - precipitation layer, mm, for the warm period of the year, determined according to SP131.13330 (for Moscow = 465mm);

ht - layer of precipitation, mm, for the cold period of the year (determines the total annual amount of meltwater) or the water reserve in the snow cover at the beginning of snowmelt, determined according to SP131.13330; (for Moscow = 225mm)

Ψ d, Ψ t - the total coefficient of runoff of rain and melt water, respectively

The total runoff coefficient Ψ d for the total runoff area is calculated as a weighted average of the partial values for runoff areas with different surface types according to Table 7.

Table 7 SP 32.13330.2012: - Runoff coefficient values for different types surfaces

When determining the average annual volume of melt water, the total runoff coefficient Ψ t from residential areas and enterprise sites, taking into account snow removal and water losses due to partial absorption by permeable surfaces during the thaw period, can be taken within the range of 0.5-0.7 (in the calculation, 0. 5).

m is the specific water consumption for washing road surfaces (assumed 0.5 for manual washing and 1.2-1.5 l/m for one mechanized washing);

K is the average number of car washes per year (for central Russia it is 100-150); F m - area of hard surfaces subjected to washing, ha;

Ψ m - runoff coefficient for irrigation water (assumed equal to 0.5)

Volume of rainwater runoff from design rain discharged to sewage treatment plants:

W very = 10h a Ψ mid F=10*10.0*0.349*7.75=270.7 m 3 (formula 8, SP32.13330.2012)

- h a - the maximum layer of precipitation for rain, the runoff from which is subjected to full purification, mm (we accept from 5-10mm, see Vodgeo);

— Ψ mid — average runoff coefficient for the calculated rain (defined as a weighted average value depending on the constant values of the runoff coefficient Ψ i for different types of surfaces according to Table 14, SP 32.13330.2012:

Table 14 SP 32.13330.2012:


Type of drain surface	Cover coefficient	Constant runoff coefficient
Waterproof surfaces (roofs and asphalt concrete pavements)	0.33-0.23 (accepted according to table 15)	0,95
Cobblestone bridges and crushed stone coverings	0,224	0,6
Cobblestone streets	0,145	0,45
Crushed stone coverings not treated with binding materials	0,125	0,4
Gravel garden paths	0,09	0,3
Ground surfaces (planned)	0,064	0,2
Lawns	0,038	0,1

The maximum daily volume of melt water, in the middle of the snowmelt period, discharged to treatment facilities:

Wt,cyt = 10h s FaΨ t K y =10*25*7.75*0.8*0.5*0.9=697.5 m 3 (formula 9, SP 32.13330.2012)

Where: 10 is the conversion factor;

h c is the layer of melt water for 10 daytime hours at a given supply, we take 25 mm (see Appendix 1, formula 10, Vodgeo);

F- runoff area, ha;

a- coefficient taking into account the unevenness of snow melting can be taken as 0.8;

Ψ t is the total coefficient of melt water runoff (assumed 0.5-0.8), 0.5 is assumed in the calculation;

K y - coefficient taking into account partial removal and removal of snow, determined by the formula:

K y = 1 - Fy /F = 1-0.775/7.75 = 0.9 (formula 10, SP 32.13330.2012)

Fy = 0.15* F=0.1*7.75=0.775

The flow rate of rainwater in rainwater sewer collectors, l/s, will be:

Q r =(Ψ mid *A*F)/t n r =0.349*384.32*7.75/(12.1) 0.59 =327.3 l/s (formula 1, section 7.4, SP 32.13330.2012 )

Where A, n are parameters characterizing, respectively, the intensity and duration of rain for a specific area. A is determined by formula 13, SP 32.13330.2012. n – determined according to table 9 SP 32.13330.2012.

Ψ mid – average runoff coefficient ( previously calculated)

t n r is the estimated duration of rain, determined by the formula:

tr = t con + t sap + tr =3+0+4.1=7.1 min (formula 14, section 7.4.5, SP 32.13330.2012)

where t con is the duration of rainwater flow to the storm water inlet (surface concentration time), ( determined by SP 32.13330.2012 p. 7.4.6: The time of surface concentration of rainwater runoff should be calculated or taken into account populated areas in the absence of intra-block closed rain networks equal to 5-10 minutes, and in their presence - equal to 3-5 minutes. When calculating the intra-quarter sewer network, the surface concentration time should be taken equal to 2-3 minutes.). In the calculation, t con = 3 min;

t gland - the same, for street gutters to the storm water inlet (if there are none within the block), determined by formula (15) SP 32.13330.2012. In the calculation it is taken equal to 0, because no street stalls;

t p – the same, along pipes up to the calculated cross-section, determined by:

0.017*410/1.7=7.1, min (formula 16, section 7.4.6, SP 32.13330.2012).

Where: l p - length of design sections of the collector, m (according to the general plan);

V p – estimated current speed in the area, m/s.

80*20 0.59 *(1+lg(0.5)/lg(150)) 1.33 =384.32 (formula 13, SP 32.13330.2012)

Where: q 20 is the intensity of rain, l/s per 1 hectare, for a given area for a duration of 20 minutes at P = 1 year (determined from Figure B.1 SP 32.13330.2012). From Figure B.1 q 20 =80;

m r is the average amount of rain per year (according to Table 9, SP 32.13330.2012). For the flat region of the west and center of the European part of Russia m r =150.;

P-period of a one-time excess of the calculated rain intensity (determined according to clause 7.4.3., table 10, 11, 12, SP32.13330.2012). In calculation P=0.5;

γ-exponent (determined according to Table 9, SP 32.13330.2012). For the flat region of the west and center of the European part of Russia γ =1.33.

Rainwater flow for hydraulic calculation of rainwater networks:

Qсal = βQr = 0.71*327.3=232.38 l/s

The flow rate of wastewater sent for treatment is determined by formula 167, manual to SNiP 2.04.03-85:

Qg=K1*K2*Qr=0.26*1.51*327.3=128.5l/s

Where: Coefficient values K 1, And K2 depending on size WITH And n For various conditions calculations of treatment facilities and storm drainage networks are given in table. 55 and 56 manual to SNiP 2.04.0-85), and the parameter values “ n" and coefficient " WITH"in fig. 26, 27 (manual to SNiP 2.04.0-85). For Moscow: C=0.85, n=0.65. We accept P och =0.1. From table 55 (manual for SNiP 2.04.0-85): K 1 =0.26.

Calculation of storm (rain) runoff is performed to determine the second flow rate and hydraulic calculation of storm sewerage based on the areas and characteristics of the catchment basins.

The specialists of Region LLC have significant experience in calculations and design of both stormwater treatment plants.

Calculation example

Rainwater flow rates qr, l/s, should be determined using the maximum intensity method (SP 32.13330.2012 Updated edition of SNiP 2.04.03-85) according to the formula:

qr= (z mid *A 1.2 *F) / t r (1.2*n-0.1) = 376.6 l/s

where zmid is the average value of the coefficient characterizing the surface of the drainage basin, determined in accordance with clause 7.3.1, zmid=0.291;

A, n - parameters determined according to clause 7.4.2

A = q 20 * 20 n *(1+ lgР/(lgm r) y = 207.7

where q20 = 70 is the rain intensity, l/s per 1 ha, for a given area for a duration of 20 minutes at P = 1 year, determined from Fig. B.1

n = 0.48 - exponent determined according to table. 9

mr = 120 - the average amount of rain per year, taken according to the table. 9;

P = 0.33 - period of one-time excess of the calculated rain intensity, taken according to Table 10;

γ = 1.33 - exponent taken according to the table. 9.

F = 6.91 - estimated runoff area, ha;

tr is the estimated duration of rain, equal to the duration of rainfall surface waters along the surface and pipes to the design section, min, and determined in accordance with clause 7.4.5.

The estimated flow rate of rainwater for hydraulic calculation of rainwater networks qcal, l/s, should be determined by formula (14)

tr = tcon + tcan + tp = 11.7 min

tcon - duration of rainwater flow to the street gutter or, if there are storm water inlets within a block, to the street collector (surface concentration time), 5 minutes, determined in accordance with clause 7.4.6

The time of surface concentration of rainwater runoff should be determined by calculation or taken in populated areas in the absence of intra-block closed rainwater networks as 5-10 minutes or in their presence as 3-5 minutes.

tсan - the same, along street gutters to the storm water inlet (if there are none within the block), determined by formula (15)

where lcan = 0 - length of tray sections, m;

tp - the same, along pipes to the calculated cross-section, determined by formula (16)

The duration of rainwater flow through the pipes to the calculated cross-section tp, min, should be determined by the formula:

where Lp is the length of the design sections of the collector, 400 m;

Vp - design current speed in the area, 1.0 m/s

The average value of the runoff coefficient zmid should be determined as a weighted average depending on the coefficients z characterizing the surface and taken from the table. 14 and 15.

	Surface name



Average coefficient value

The estimated flow rate of rainwater for the hydraulic calculation of rainwater networks qcal, l/s, should be determined using formula 12:

Qcal=β*qr = 286.2 l/s

where β is a coefficient that takes into account the filling of the free capacity of the network at the moment the pressure regime occurs and is determined from Table 8, β = 0.76

We select the estimated diameter of the pipe in front of the tank and treatment facilities.

Outlet diameter polyethylene pipes is accepted on the basis of flow rate Qcal = 286.2 l/s according to the tables of A.Ya. Dobromyslov “Tables for hydraulic calculations of pipelines made of polymer materials” Volume 2 “Free-flow pipelines” Moscow publishing house VNIIMP 2004

Quantitative characteristics of surface runoff from the territory.

Annual volume of surface runoff.

The calculation of the annual volume of rain, melt and drainage runoff was carried out taking into account the Federal State Unitary Enterprise "Research Institute VODGEO" "Recommendations for the calculation of systems for the collection and disposal and treatment of surface runoff from residential areas, enterprise sites and the determination of release conditions" (1), SP 131.13330.2012 Updated version SNiP 23-01-99* “Building climatology” (2), as well as SP 32.13330.2012 Updated version of SNiP 2.04.03-85 “Sewerage. External networks and structures" (3).

The average annual volume of surface wastewater generated on the site during the period of rainfall and snow melting is determined by the formula:

Wg = Wd + Wt + Wm

The average annual volume of rain (Wd) and melt water (Wt) is determined by the formulas:

Wd = 10hd ψd F =18677.5 m 3 /year;

Wt = 10htψtF = 9770.7 m 3 /year;

Ψ - average runoff coefficient, clause 5.1.3-5.1.5 (1), clause 7.2.1-7.2.6 (3);

where F = 6.91 ha - total area drain

hd - precipitation layer, mm, for the warm period of the year, determined from Table 4.1 (2), 423 mm;

ht - precipitation layer, mm, for the cold period of the year, table. 3.1 (2), 202 mm;

ψd = 0.639 - average runoff coefficient, clause 7.2.3 of table 7 (3);

ψт = 0.7 - average runoff coefficient, clause 7.2.5 (3);

The average runoff coefficient ψ d should be determined as a weighted average depending on the coefficients ψ d characterizing the surface and taken from the table. 7(3).

Table No. 3

	Surface name
	Roofing of buildings and structures (4.66 hectares), asphalt concrete pavement of roads (1.55 hectares)

Total:
Average coefficient value

The total annual volume of irrigation water (Wm), m3, flowing from the drainage area is determined by the formula:

Wм = 10 m k FмΨм = 1395.0 m 3 /year

where m is the specific water consumption for washing road surfaces (usually 1.2-1.5 l/m2 per wash);

k is the average number of car washes per year (for central Russia it is about 150);

Fm - area of hard surfaces subject to washing, 1.55 hectares;

Ψm - runoff coefficient for irrigation water (assumed equal to 0.5);

The average annual volume of surface runoff will be:

Wg =29843.2 m 3 /year

Having the average annual volume of surface runoff, we convert it into an average daily volume.

The average daily volume of annual flow is 81.8 m3/day

The maximum daily volume of rain runoff from the calculated rain Woch, m3, discharged to treatment facilities from residential areas and enterprise sites, is determined by the formula:

Woch = 10*ha*F*Ψmid = 574.0 m 3 /day

where ha is the maximum layer of precipitation during rain, mm, the runoff from which is treated in full, 13.0 mm;

Ψmid - average runoff coefficient for the calculated rain (defined as a weighted average depending on the constant values of the runoff coefficient Ψi, for different types of surfaces according to Table 7, clause 7.2.3 (3)), 0.639;

F - total drainage area, 6.91 ha

Maximum hourly volume of rainwater runoffWh.h = 574.0/6 = 95.7 m 3 /h

Calculation of melt water

Maximum daily volume of melt water Wt.day, m3, in the middle of the snowmelt period, discharged to treatment facilities from residential areas and industrial enterprises, is determined by the formula:

Wt.day =10 ΨtKу F hc = 69.1 m 3 /day

where Ψт is the general coefficient of melt water runoff (assumed 0.5-0.7);

F - drainage area, 6.91 ha;

Ku - coefficient taking into account partial removal and removal of snow is determined by the formula:

Ku=1 - Fu/F = 0.10

Fu - area cleared of snow (including the area of roofs equipped with internal drains) 6.21 hectares;

hc - layer of melt water for 10 daytime hours, mm, is taken depending on the location of the object. The boundaries of climatic regions are determined by the snow runoff zoning map given in clause 5.2.6 (1) and Appendix 1 (1), as well as Fig. B.1 (3), 20 mm;

Useful information and interesting articles:

Photos of drainage and sewerage:

The main difficulties and mistakes when designing yourself (with your own hands)		Solutions LLC "Region"
	Lack of an agreed upon design of the Sanitary Protection Zone (SPZ)		We will analyze the current situation and prepare Terms of Reference for the SPZ project. If necessary, we will carry out the design of the sanitary protection zone and coordinate it.
	Lack of metering devices and objective (calculated) data on the required productivity.		We will collect all the necessary data, carry out calculations and present it to the customer for consideration. If necessary, we will carry out temporary installation of metering devices.
	Lack of title documents for land.		We will assist in the preparation of documentation and, if necessary, include it in the design specifications.
	Inaccuracies in the preparation of the Technical Specifications: all necessary research was not taken into account, the above listed documents were not taken into account.		We will analyze the current situation and prepare the correct technical specifications.
	The price justification was not carried out correctly, based on commercial proposals from non-specialized organizations, without taking into account the fulfillment of requirements technical specifications, the need to inspect buildings and structures, etc.		We will prepare an estimate for design and survey work and inspection, according to reference price guides.
	Survey, survey, design - carried out different companies- this causes delays in deadlines and the appearance of additional work.		We have significant experience and qualifications to organize a full range of design and survey work. The Region company has SRO approvals for both design and survey work. We are guaranteed to provide a positive expert opinion and support during construction and installation work.


To date, Region LLC has more than 150 successfully completed survey and design work. Our customers are the largest organizations in Russia.Numerous official reviews from organizations confirm our professionalism and responsibility in working with customers.

COST OF PROJECT DEVELOPMENT

To determine the basic (initial) cost of design estimates and survey work, Region LLC uses a time-tested method: drawing up estimates for design and survey work using reference price reference books. The estimated cost of design and survey work is a justified initial cost of work, which is clarified in the process of clarifying the scope of work and negotiations. An estimate for design and survey work compiled according to reference price reference books can serve as a justification for the price during the competitive procedure in accordance with Federal Law No. 44 and No. 223.



	Assistance in completing applications for participation in Federal Target Programs (FTP).	We make all technical and technological decisions based on variant design and comparison of all technical and economic parameters, including operational ones.
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The Region LLC company is part of a number of large design and construction holdings and is ready to implement turnkey projects throughout Russia.

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30%	Costs of construction and installation works. Based on variant design and modern technologies we select the optimal solution. 3D modeling technologies help to avoid waste of materials and minimize the likelihood of errors.

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20%	Time during construction and installation work. The decisions made by our engineers and architects are not only reliable and aesthetic, but also thought out in terms of convenience and speed of implementation (flexible solutions in terms of work execution).

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and financial liability for failure to meet deadlines.

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HOW WE DESIGN

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The use of licensed software guarantees information security, legality of work and reduces the risks of company closure due to inspections by regulatory authorities.

Every year, precipitation falls on the roofs of houses in the form of rain and snow. Sometimes more abundant, sometimes less. IN different regions, depending on their geographical location, different amounts of precipitation fall. Is it possible to calculate the volume of drainage from the roof and why is this necessary?

Precipitation in different regions differs in its volume and frequency.

Calculation of storm drains

Storm drains are rain and melt water that enters drainage pipes.

Calculation of rainwater flowing from the surface of the building is necessary to determine the throughput capacity of the pipe when installing storm sewers. The calculation is important when determining the volume of a liquid-receiving container (with an autonomous sewage system).

The correct calculation is regulated by SNiP 2.04.01-85* section “Internal drains” (new document SP 30.13330.2011) and SNiP 2.04.03-85 regarding rainwater flow (new document SP 32.13330.2011).

It is reliable that the flow rate of storm water from the roofs of houses can be calculated using two different formulas: the first is set out in SNiP 2.04.01-85* (internal), the second in SNiP 2.04.03-85 (external). At the same time, under equal conditions, according to the first formula, the consumption is significantly higher.

Calculation using an internal formula determines the flow rate as the product of the volume of precipitation by . The external formula is more complex. There are many coefficients that reduce the calculated consumption.

It is better to calculate the rainwater required for drainage using the formulas given in SNiP 2.04.01-85:

At autonomous system sewerage, it is more expedient to collect water for household needs in a separate container.

for roofs with a slope of up to 1.5% inclusive – Q=Fq20 / 10000;
for roofs with a slope of more than 1.5% - Q=Fq5 / 10000;

F – drainage area, sq.m.;

q20 – rain intensity, l/s per 1 ha (for a given area), lasting 20 minutes with a period of one-time excess of the calculated intensity equal to 1 year (accepted in accordance with SNiP 2.04.03-85);

q5 – rain intensity, l/s per 1 hectare (for a given area), lasting 5 minutes with a period of one-time excess of the calculated intensity equal to 1 year, determined by the formula:

where n is the parameter used in accordance with SNiP 2.04.03-85.

When calculating the drainage area, it is necessary to take into account 30% of the total area of the vertical walls adjacent to the roof and the walls rising above it.

After calculating rain and melt water and obtaining the result, the required pipe diameter is selected. This is necessary to ensure that the pipe capacity does not turn out to be less than required. The liquid flow per drainage riser should not exceed the data given in the table.

Basic wastewater disposal methods

Device diagram drainage system. When calculating the drainage area, it is necessary to take into account 30% of the total area of the vertical walls adjacent to the roof and the walls rising above it.

Two main methods are used to remove precipitation from the surface of buildings.

The first method is point abduction. This method is based on draining water masses from the surface of the building by creating slopes towards receiving funnels. Next to the drainage system.

The second method is linear abduction. According to this method, all water from the roof surface flows to the water inlet gutter (such gutters are made with a slope towards the drainpipe) and is discharged through it into the drainage system. The water goes into external storm sewer networks. In the absence of such, wastewater is received in open trays near the building.

With an autonomous sewage system, it is more expedient to collect water for household needs in a separate container. The container must be equipped with an overflow system.

Which method should I use?

Point drainage is used on flat roofs. Flat roofs are usually designed with internal gutters located in the center of the slab. The roof planes of such roofs are made with a slope. Water moves along roofing surfaces and gutters to the receiving pipe. At least two funnels must be installed on the plane.

Linear drainage is designed on pitched roofs. Roofs can be single-pitched, gable, hipped and even more complex. This type of roof is often designed with external downpipes. Can be found with an internal drain. The bottom of the roof, extending beyond the boundaries of the external walls, is called the “overhang”. The bottom edge is called the “drip edge”. On complex types roofs, at the junction of two surfaces, a gutter is formed through which storm water flows to the gutters. This gutter is called the valley.

For any type of roof, the distance between funnels should not exceed 48 m.

After calculating the water flow for the entire roof and determining the method of drainage, the size of the gutters and the number of funnels are selected. The total consumption is divided by the funnel consumption according to the passport (at different manufacturers this figure is about 7-10 l/s).