Water Self-Sufficiency of Neighbourhood using Artificial Water Ponds

Download Full-Text PDF Cite this Publication

Text Only Version

Water Self-Sufficiency of Neighbourhood using Artificial Water Ponds

Case Study of Vaijapur, Aurangabad

Saumitra Kapil Jadhav

Department of Architecture M.G.M.Us Jawaharlal Nehru Engineering College,

Aurangabad, India

Prof. Medha Naik

Department of Architecture M.G.M.Us Jawaharlal Nehru Engineering College,

Aurangabad, India

Abstract Neighbourhoods use water for drinking, cooking, bathing, washing, and gardening in India. They significantly rely on water sources like rivers, lakes, ponds, and underground water reserves. Due to increasing population and adverse climate changes in recent years, most water resources are on the brink of drying out; in some cases, they already have.

Rainwater is one of the most underutilized types of water resources with minimal efforts made for its harvest and storage. While some residential buildings like houses and apartments in neighbourhoods are installed with rainwater harvesting measures that collect water from roof runoffs, a significant amount of rainwater falls on impervious hard covered areas like pavements, roads, and other forms of built structures in the same vicinity which ends up in the sewer line and gets contaminated. This rainwater runoff has the potential to fulfil rising water demands on a neighbourhood scale and can be harvested and stored in artificial water ponds and used throughout the year, thereby enabling water self-sufficiency of the neighbourhoods. Such artificial water ponds will be beneficial in fulfilling the water demands of emerging and existing neighbourhoods in Vaijapur, a tehsil in Aurangabad, Maharashtra, where residents are heavily dependent on groundwater reserves during the summer season.

Keywords Water self-sufficiency; neighbourhoods; rainwater harvesting; rainwater runoff; artificial water ponds

  1. INTRODUCTION

    India has only 4% of the total freshwater resources in the world which provides for the water demand of its 1.3 billion population. With increasing population and decreasing freshwater reserves, various regions of the country are experiencing severe drought or drought-like conditions. Vaijapur, a municipal council in the district of Aurangabad that lies in the region of Marathwada in Maharashtra, India, experienced a severe drought in 2013 and a normal drought in 2014 [1] due to extreme water scarcity. Due to insufficient surface water resources, Vaijapur faces a severe water crisis and finding reliable alternatives becomes critical.

    1. Literature Review

      The feasibility of the project and water harvesting technique was assessed by referring to the paper Assessment of Water Supply and Sanitation by Using Artificial Ponds in Nashik District, India [2] which used artificial water ponds to cater to the drinking water demands of the 4,500 people of Janori

      village in Dindori (20° 12' N latitude and 73° 43' E longitude) in the Nashik district of Maharashtra. The paper concluded that runoff water is drinkable based on the results of the tests carried out in the study area. The results were within the limit of BIS standards and the use of a storage pond system will provide the village with good quality drinking water.

    2. Water Source

      The primary water source for Vaijapur municipal council is a dam on the Narangi River, which is a tributary of the River Godavari. The dam provides water for agriculture and domestic use. Groundwater pumped through borewells is another source of water in the region, and in some cases, the primary source of water.

      Fig. 1. Narangi Sarangi Dam Satellite Image (May-2014)

      Fig. 2. Narangi Sarangi Dam Satellite Image (Mar-2016)

      Fig. 3. Narangi Sarangi Dam Satellite Image (May-2017)

      Fig. 4. Narangi Sarangi Dam Satellite Image (Nov-2018)

      Fig. 1 to Fig. 4 shows the dry state of the river and the dam (19°5559 N, 74°4249 E) in recent years when the region experienced severe drought-like conditions. During such drought-like conditions, the populations water demands put a strain on groundwater sources, which in some instances, dry out due to excessive pumping of water.

    3. Rainfall

      The region receives rainfall from June to September, with the average, minimum, and maximum rainfall being 517.45 mm, 150 mm, and 918 mm respectively [3]. The Vaijapur tehsil experienced severe water scarcity in 2013 (severe drought) and 2014 (normal drought) when the annual average rainfall was

      500.6 mm and 566.7 mm respectively [1]. Thus, efficient utilisation of rainwater becomes essential to fulfil the water demands in the region.

    4. Rapid Urbanization

    In recent years, numerous neighbourhoods have emerged within Vaijapur municipal council's limits. As per the data collected during the site visit of the study area, some residential projects in the vicinity have proposals of constructing 250 to 500 dwelling units (row houses), which will lead to migration from surrounding settlements to the town, thereby increasing water demands. Fig. 5, Fig. 6, Fig. 7, and Fig. 8 show the construction of multiple dwelling units (row houses) in two different neighbourhoods in Vaijapur.

    Fig. 5. Jeevan Ganga Society Satellite Map (May-2014)

    Fig. 6. Jeevan Ganga Society Satellite Map (May-2021)

    Fig. 7. Laxmi Narayan Nagar Satellite Map (May-2014)

    Figure 8. Laxmi Narayan Nagar Satellite Map (May-2021)

  2. METHODS

    As rapid construction of neighbourhoods is a common sighting in Vaijapur municipal council's limits, selecting an emerging neighbourhood development project and designing a rainwater harvesting module for the same will help in analysing the efficiency of artificial water ponds in catering to the needs of the neighbourhoods water demands.

    1. Site Details

      A newly proposed residential neighbourhood project is under development (fig. 9 and fig. 10) on the Aurangabad-Shirdi Highway in Vaijapur, Aurangabad (19°54'36.47"N latitude and 74°44'6.84"E longitude). Fig. 10 shows the identified project area that is spread over 89925.00 m2 (22.22 acres). Out of the total project area, 41206.51 m2 (10.18 acres) is allotted for residential development (after deduction prescribed by the local authorities and development by-laws), internal access roads cover an area of 24281.79 m2 (6.00 acres), and land reserved for open spaces, amenity space and school is 8,937.67 m2 (2.20 acres), 8,937.70 m2 (2.20 acres) and 4,000.90 m2 (0.98 acres) respectively.

    2. Population

      The identified neighbourhood has plots for development ranging from 70 m2 to 600 m2 with an average of one household per 100 m2 area. In India, the average household population is estimated at around 4.8 to 5.00 persons per household [4]. Based on the given data, Table 1 shows the estimated population of the identified neighbourhood.

      TABLE 1. ESTIMATED NEIGHBOURHOOD POPULATION

      Total Plotted area for Residential Development

      Total Household (1/100 m2)

      Average Population per Household

      Estimated Population

      41,206.51 m2

      412.06

      4.8 to 5.00

      1978 to 2060

      (Considering 2060 as neighbourhood population for design calculations)

    3. Water Demand

    As prescribed in the National Building Code (NBC) of India, 2016 Volume II [5], water quantity of 70 to 100 litres per person/capita per day (lpcd) is considered adequate for domestic use and 45 lpcd for flushing needs. Based on the given

    Fig. 9. Newly ProposedResidential Neighbourhood Development along Aurangabad-Shirdi Highway

    Figure 10. Land-Use Pattern of the Proposed Residential Neighbourhood Development

    data, Table 2 shows the estimated water demand of the identified neighbourhood.

    Water Demand Per Day (m3)

    Annual Water Demand (m3)

    Estimated Population

    (excluding water for flushing systems)

    (including water for flushing systems)

    (excluding water for flushing systems)

    (including water for flushing systems)

    2060

    206.00

    298.70

    75190.00

    109025.50

    TABLE 2. ESTIMATED NEIGHBOURHOOD WATER DEMAND

    For example,

    Annual Runoff volume for a concrete pavement with a surface area of 1000 m2 and 500 mm annual rainfall is calculated as,

    Runoff Volume = 1000 × 0.95 × 0.50 = 475.00 m3

    Table 5 to Table 12 shows the runoff calculations and rainwater harvesting potential of the identified neighbourhood in each of the four cases as shown in Table 3.

    60,000.00

    47,628.48

    50,000.00

    39,324.25

    40,000.00

    28,419.46 32,442.51

    30,000.00

    20,000.00

    E. Comparative Analysis of the Cases

    (Considering 100 lpcd water demand in case of residences excluding flushing systems and 145 lpcd in case of residences including flushing systems)

    D. Rainwater Runoff Potential

    Rainwater is one of the few scarce sources of water in Vaijapur Taluka, with the region receiving around 517.45 mm of average annual rainfall [3]. From Fig.10 in the case of the identified neighbourhood, rainwater runoff can potentially be harvested

    10,000.00

    Case I:

    517.45 mm (avg.)

    Case II:

    590.70 mm (2019)

    In cu.m.

    Case III:

    867.20 mm (2020)

    Case IV: 716 mm (2021)

    from surfaces like rooftops (41206.51 m2), internal access roads (24281.79 m2), open spaces (8,937.67 m2), amenity space (8,937.70 m2) and plot of land reserved for school (4,000.90 m2). For calculating the potential of rainwater harvesting by collecting rainwater runoff, four cases have been presented depending on the rainfall trends in the region, taking into consideration the average annual rainfall of 517.45 mm [3] and 590.70, 867.20 mm and 716.00 mm of annual rainfall in the years 2019 [6], 2020 [7] and 2021 [8] respectively. Table 3 shows the rainfall data considered in each of the cases.

    TABLE 3. CASES CONSIDERED FOR RUNOFF CALCULATIONS

    Case

    I

    II

    III

    IV

    Rainfall (in mm)

    517.45

    590.70

    867.20

    716.00

    Year

    2019

    2020

    2021

    The formula for calculating rainwater runoff volume is [9],

    Runoff Volume= Surface area × Runoff Coefficient × Rainfall

    The runoff coefficient of different types of surfaces [9] is given in Table 4 which is considered in calculating the rainwater harvesting potential in each of the four cases.

    TABLE 4. RUNOFF COEFFICIENT OF SURFACE TYPES

    Fig. 9. Rainwater runoff harvesting potential of the neighbourhood in each of

    63.34

    52.30

    37.80

    26.07

    43.15

    29.76

    43.69

    36.07

    the specified cases

    70.00

    60.00

    50.00

    40.00

    30.00

    20.00

    10.00

    Case I: 517.45 Case II: 590.70

    mm (avg.)

    Case III: Case IV: 716

    867.20 mm mm

    (2020) (2021)

    Excluding Water for Flushing Systems (%)

    Including Water for Flushing Systems (%)

    mm

    (2019)

    Fig. 10. Water Demand Satisfied in each of the specified cases

    Fig. 11 and Fig. 12 show the comparison of the rainwater harvesting potential of the identified neighbourhood and the per cent of the water demands that can be satisfied based on the rainfall data in each of the four cases respectively.

    Surface

    Surface Type

    Runoff Coefficient

    Rooftop

    Concrete Pavement

    0.95

    Internal Access Roads

    Cemented/Tiled Roof

    0.95

    Open Spaces

    Turf, Average (1 to 3% Slope)

    0.35

    Amenity Space

    Open grid grass pavement

    0.50

    Land reserved for school

    Turf flat (0 to 1% slope)

    0.25

    TABLE 5. NEIGHBOURHOODS RAINWATER RUNOFF CALCULATIONS FOR CASE I

    RAINWATER RUNOFF CALCULATIONS WITH 517.45 mm AVERAGE ANNUAL RAINFALL

    Surface

    Total Area (in m2)

    Area Available for Harvesting (in m2)

    Annual Average Rainfall (in mm)

    Runoff Co- efficient

    Gross Rainwater Harvested

    (in m3)

    Precipitation/ Weather Loss (10%)

    Net Rainwater Harvested

    (in m3)

    Rooftop

    41,206.51

    30,904.88

    517.45

    0.95

    15192.14

    1519.21

    13672.93

    Internal Access Roads

    24,281.79

    24,281.79

    517.45

    0.95

    11936.38

    1193.64

    10742.74

    Open Spaces

    8,937.67

    8,937.67

    517.45

    0.35

    1618.68

    161.87

    1456.81

    Amenity Space

    8,937.70

    8,937.70

    517.45

    0.50

    2312.41

    231.24

    2081.17

    School

    4,000.90

    4,000.90

    517.45

    0.25

    517.57

    51.76

    465.81

    Total

    87,364.57

    77,062.94

    31577.18

    3157.72

    28419.46

    TABLE 6. NEIGHBOURHOOD'S RAINWATER RUNOFF HARVESTING POTENTIAL IN CASE I

    WATER DEMAND SATISFIED WITH 517.45 mm AVERAGE ANNUAL RAINFALL

    Demand Type

    Annual Neighbourhood Water Demand (in m3)

    Total Rainwater Harvesting Potential (in m3)

    Water Demand Satisfied (in %)

    Excluding Water for Flushing

    75190.00

    28419.46

    37.80

    Including Water for Flushing

    109025.50

    26.07

    Difference

    33835.50

    11.73

    Table 7. NEIGHBOURHOODS RAINWATER RUNOFF CALCULATIONS FOR CASE II

    RAINWATER RUNOFF CALCULATIONS WITH 590.70 mm ANNUAL RAINFALL (2019)

    Surface

    Total Area (in m2)

    Area Available for Harvesting (in m2)

    Annual Average Rainfall (in mm)

    Runoff Co- efficient

    Gross Rainwater Harvested

    (in m3)

    Precipitation/ Weather Loss (10%)

    Net Rainwater Harvested

    (in m3)

    Rooftop

    41,206.51

    p>30,904.88

    590.70

    0.95

    17342.74

    1734.27

    15608.46

    Internal Access Roads

    24,281.79

    24,281.79

    590.70

    0.95

    13626.09

    1362.61

    12263.48

    Open Spaces

    8,937.67

    8,937.67

    590.70

    0.35

    1847.82

    184.78

    1663.04

    Amenity Space

    8,937.70

    8,937.70

    590.70

    0.50

    2639.75

    263.97

    2375.77

    School

    4,000.90

    4,000.90

    590.70

    0.25

    590.83

    59.08

    531.75

    Total

    87,364.57

    77,062.94

    36047.23

    3604.72

    32442.51

    Table 8. NEIGHBOURHOOD'S RAINWATER RUNOFF HARVESTING POTENTIAL IN CASE II

    WATER DEMAND SATISFIED WITH 590.70 mm ANNUAL RAINFALL (2019)

    Demand Type

    Annual Neighbourhood Water Demand (in m3)

    Total Rainwater Harvesting Potential (in m3)

    Water Demand Satisfied (in %)

    Excluding Water for Flushing

    75190.00

    32442.51

    43.15

    Including Water for Flushing

    109025.50

    29.76

    Difference

    33835.50

    13.39

    Table 5. NEIGHBOURHOODS RAINWATER RUNOFF CALCULATIONS FOR CASE III

    RAINWATER RUNOFF CALCULATIONS WITH 867.20 mm ANNUAL RAINFALL (2020)

    Surface

    Total Area (in m2)

    Area Available for Harvesting (in m2)

    Annual Average Rainfall (in mm)

    Runoff Co- efficient

    Gross Rainwater Harvested

    (in m3)

    Precipitation/ Weather Loss (10%)

    Net Rainwater Harvested

    (in m3)

    Rooftop

    41,206.51

    30,904.88

    867.20

    0.95

    25460.68

    2546.07

    22914.61

    Internal Access Roads

    24,281.79

    24,281.79

    867.20

    0.95

    20004.31

    2000.43

    18003.88

    Open Spaces

    8,937.67

    8,937.67

    867.20

    0.35

    2712.76

    271.28

    2441.49

    Amenity Space

    8,937.70

    8,937.70

    867.20

    0.50

    3875.39

    387.54

    3487.85

    School

    4,000.90

    4,000.90

    867.20

    0.25

    867.40

    86.74

    780.66

    Total

    87,364.57

    77,062.94

    52920.53

    5292.05

    47628.48

    TABLE 10. NEIGHBOURHOOD'S RAINWATER RUNOFF HARVESTING POTENTIAL IN CASE III

    WATER DEMAND SATISFIED WITH 867.20 mm ANNUAL RAINFALL (2020)

    Demand Type

    Annual Neighbourhood Water Demand (in m3)

    Total Rainwater Harvesting Potential (in m3)

    Water Demand Satisfied (in %)

    Excluding Water for Flushing

    75190.00

    47628.48

    63.34

    Including Water for Flushing

    109025.50

    43.69

    Difference

    33835.50

    19.66

    TABLE 11. NEIGHBOURHOODS RAINWATER RUNOFF CALCULATIONS FOR CASE IV

    RAINWATER RUNOFF CALCULATIONS WITH 716.00 mm ANNUAL RAINFALL (2021)

    Surface

    Total Area (in m2)

    Area Available for Harvesting (in m2)

    Annual Average Rainfall (in mm)

    Runoff Co- efficient

    Gross Rainwater Harvested

    (in m3)

    Precipitation/ Weather Loss (10%)

    Net Rainwater Harvested

    (in m3)

    Rooftop

    41,206.51

    30,904.88

    716.00

    0.95

    21021.50

    2102.15

    18919.35

    Internal Access Roads

    24,281.79

    24,281.79

    716.00

    0.95

    16516.47

    1651.65

    14864.83

    Open Spaces

    8,937.67

    8,937.67

    716.00

    0.35

    2239.78

    223.98

    2015.80

    Amenity Space

    8,937.70

    8,937.70

    716.00

    0.50

    3199.70

    319.97

    2879.73

    School

    4,000.90

    4,000.90

    716.00

    0.25

    716.16

    71.62

    644.54

    Total

    87,364.57

    77,062.94

    43693.61

    4369.36

    39324.25

    TABLE 12. NEIGHBOURHOOD'S RAINWATER RUNOFF HARVESTING POTENTIAL IN CASE IV

    WATER DEMAND SATISFIED WITH 716.00 mm ANNUAL RAINFALL (2021)

    Demand Type

    Annual Neighbourhood Water Demand (in m3)

    Total Rainwater Harvesting Potential (in m3)

    Water Demand Satisfied (in %)

    Excluding Water for Flushing

    75190.00

    39324.25

    52.30

    Including Water for Flushing

    109025.50

    36.07

    Difference

    33835.50

    16.23

    1. Artificial Water Pond Design

      Fig. 11. Typical Layout of an artificial water pond

      The identified neighbourhood site at maximum can potentially harvest up to 47,628.48 m3 of rainwater and satisfy up to 63% (excluding water for flushing systems) or 43% (including water for flushing systems) of the total water demand based upon the calculation shown in Table 9 and Table 10.

      Fig. 13 shows a typical layout and components of an artificial water pond and the following are the parameters that are essential in designing and constructing the pond:

      1. Volume of the Pond

        Based on the calculated data (Table 5 to Table 12), an artificial water pond of around 50,000 m3 volume will be sufficient to store the neighbourhoods maximum rainwater runoff calculated, i.e. 47,628.47 m3 with an additional 5% of excess storage volume.

      2. Shape of the Pond

        Artificial water ponds are mainly constructed in three shapes

        i.e. square, rectangular and inverted cones. However, as curved shape offers difficulties in construction, either square or rectangular shapes are normally adopted wherein square ponds are more economical than rectangular ponds [10]. In the case of

        the sidewalls of an artificial water pond, gradually inclined walls are preferred over vertical sidewalls, depending upon the

    2. Rainwater Runoff Harvesting Process

    Water Runoff

    angle of repose of the soil, as they are more efficient in resisting the water pressure exerted on them, thereby giving the artificial water pond a trapezoidal prism shape.

    1. Dimension of the Pond

      The dimensions of the artificial water pond can be calculated using the prismoidal formula based on Fig. 14 [10].

      (rooftops,inter nal roads,etc.)

      Overhead Water tank

      Distribution

      Stormwater drains

      Filtration tank

      Screening

      Tank

      Artificial Water Pond

      Figure 13. Rainwater Harvesting Process Flow-Chart

      Fig. 12. Cross-section of Artificial Water Pond for estimation of surface and bottom area and sizes

      Prismoidal Formula: V = A + 4B + C × D — (1)

      6

      Where,

      V = volume of excavation (m3)

      A = area of excavation at the ground surface (m2)

      B = area of excavation at the mid-depth point (D/2) (m2) C = area of the excavation at the bottom of the pond (m2) D = average depth of the pond (m).

      For constructing artificial water of approximately 50,000 m3 of volume consider (deeper ponds are preferable to avoid water loss due to evaporation),

      D = 9 m

      A = 80 × 80 m = 6,400 m2

      B = 75 × 75 m = 5,625 m2

      C = 70 × 70 m = 4,900 m2

      From equation 1,

      6400 + (4 × 5625) + 4900

      V = × 9 = 50700 m3

      6

    2. Lining of the Pond

    The lining is essential in artificial water ponds to avoid seepage of water into the ground. The lining of the pond is generally done using Low-Density Polyethylene (LDPE) or 500-micron High-Density Polyethylene (HDPE) sheets or in reinforced cement concrete (RCC). Though lining done in polyethylene (PE) sheets are more economical than RCC lining, PE sheets are prone to punctures, which can result in rapid loss of stored rainwater. Therefore, for avoiding such instances, RCC lining shall be preferred over PE sheet lining as it is a comparatively more efficient and durable solution.

    (Artificial Water Pond overflow drain shall be connected to percolation tank for recharging groundwater with overflowing runoff water)

  3. CONCLUSION

    By incorporating rainwater runoff harvesting techniques and storing it in an artificial water pond on-site, the identified neighbourhood site can achieve around 63% (excluding water for flushing systems) or 43% (including water for flushing systems) of water self-sufficiency and avoid dependency on local water grids for a period of 5 to 8 months. This technique can be implemented in other emerging neighbourhood developments in the region or any other region that experiences water shortages. Such strategies can also reduce excess extraction of ground and surface water reserves and help in replenishing the same. In addition to this, recycling and reusing discharged grey and black water on-site can further reduce the water needed for flushing systems in the neighbourhood, as the same water can be treated and reused multiple times.

  4. REFERENCE

[1] Gaikwad, S., Kale, K., & Ambedkar, B. (2015). Agricultural drought assessment of post monsoon season of vaijapur taluka using landsat 8.

Https://doi.org/10.15623/IJRET.2015.0408069

[2] Kadbhane, S. (2014, February 19). Assessment of Water Supply and Sanitation by Using Artificial Ponds in Nashik District, India.

[3] Aher, K. (2015). Water Level Fluctuation in the Narangi Watershed of Vaijapur Tahsil, District Aurangabad, INDIA. Universal Journal of Environmental Research and Technology, 5, 278284.

[4] Census of India: F Series: Household Tables. (n.d.). Retrieved 6 April 2022, from https://censusindia.gov.in/tables_published/HH-

Series/hh_series_tables_20011.html

[5] India-national-building-code-nbc-2016-vol-2.pdf. (n.d.). Retrieved 6 April 2022, from https://pusprajbhatt.files.wordpress.com/2017/12/india- national-building-code-nbc-2016-vol-2.pdf

[6] Chapter_9.pdf. (n.d.). Retrieved 6 April 2022, from https://www.imdpune.gov.in/Clim_Pred_LRF_New/Reports/Monsoon_ Report_2019/Chapter_9.pdf

[7] Monsoon Report 2020.pdf. (n.d.). Retrieved 6 April 2022, from https://www.imdpune.gov.in/Clim_Pred_LRF_New/Reports/Monsoon% 20Report%202020.pdf

[8] Maharashtra: Marathwada gets 131% of normal rainfall, highest among 6 divisions. (2021, September 7). The Times of India. https://timesofindia.indiatimes.com/city/aurangabad/marathwada-gets- 131-of-normal-rainfall-highest-among-6- divisions/articleshow/85995039.cms

[9] Green Home BuildersIGBC Green Homes in India | IGBC. (n.d.). Retrieved 19 April 2022, from https://igbc.in/igbc/redirecthtml.htm?Redval=showgreenhomesnosign

[10] Farm ponds technical bulletin 2012.pdf. (n.d.). Retrieved 6 April 2022, from http://www.nicra-

icar.in/nicrarevised/images/Books/Farm%20ponds%20technical%20bull etin%202012.pdf

Leave a Reply

Your email address will not be published.