An integrated approach to assess the dynamics of a peri-urban watershed influenced by
wastewater irrigation
Jampani Mahesh1*, Priyanie Amerasinghe1 and Paul Pavelic2
1
International Water Management Institute (IWMI), Hyderabad Office, Patancheru, Hyderabad,
502 324, Andhra Pradesh, India
2
International Water Management Institute (IWMI), Southeast Asia Regional Office, Vientiane,
Lao PDR
*
Corresponding author:
Jampani Mahesh, International Water Management Institute (IWMI), Hyderabad Office,
Patancheru, Hyderabad, 502 324, Andhra Pradesh, India. Phone: 0091 40 3071 3734, Email:
j.mahesh@cgiar.org
1
Abstract
In many urban and peri-urban areas of India, wastewater is under-recognized as a major water
resource. Wastewater irrigated agriculture provides direct benefits for the livelihoods and food
security of many smallholder farmers. A rapidly urbanizing peri-urban micro-watershed (270 ha)
in Hyderabad was assessed over a 10-year period from 2000 to 2010 for changes in land use and
associated farming practices, farmer perceptions, socio-economic evaluation, land-use suitability
for agriculture and challenges in potential irrigated area development towards wastewater use.
This integrated approach showed that the change in the total irrigated area was marginal over the
decade, whereas the built-up area within the watershed boundaries doubled and there was a
distinct shift in cropping patterns from paddy rice to paragrass and leafy vegetables. Local
irrigation supplies were sourced mainly from canal supplies, which accounted for three-quarters
of the water used and was largely derived from wastewater. The remainder was groundwater
from shallow hard-rock aquifers. Farmer perception was that the high nutrient content of the
wastewater was of value, although they were also interested to pay modest amounts for
additional pre-treatment. The shift in land use towards paragrass and leafy vegetables was
attributed to increased profitability due to the high urban demand. The unutilised scrubland
within the watershed has the potential for irrigation development, but the major constraints
appear to be unavailability of labour and high land values rather than water availability. The
study provides evidence to support the view that the opportunistic use of wastewater and
irrigation practices, in general, will continue even under highly evolving peri-urban conditions,
to meet the livelihood needs of the poor driven by market demands, as urban sprawl expands into
cultivable rural hinterlands. Policy support is needed for enhanced recognition of wastewater for
2
agriculture, with flow-on benefits including improved public health and protection of ecosystem
services.
Keywords:
Peri-urban agriculture, wastewater, land use dynamics, hydrology, socio-economics, farmer
perceptions
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1. Introduction
Human activities in many regions of the world vastly alter the state and functions of natural
watersheds and their ecosystems (Rao and Pant, 2001). The distribution of fluxes in the
watersheds and their ecosystems have also been altered spatially and temporally because of
conversion of wetlands and forest land to urban or agricultural land, concentrated industrial
development, vast development in hydrological pathways and excessive application of fertilizers
and pesticides (Karr et al., 1986; Naiman et al., 1995; He et al., 2000). The well-known fluxes
include temperature, evapotranspiration, solar radiation, wind speed, precipitation, surface
runoff, discharge, soil erosion, recharge, percolation, toxins and nutrient availability (Hobbs
1997, He et al., 2000). In the peri-urban watersheds, these fluxes will be even more disturbed
with the concentrated and continuous anthropogenic impacts.
Wastewater use in peri-urban agriculture is a common practice in developing countries (RaschidSally and Jayakody, 2009; Qadir et al., 2010). A large number of rivers and lakes in India receive
either partially treated or untreated water from growing urban agglomerations, converting
ephemeral water courses into perennial ones (CPCB 2009). Peri-urban farmers are, by far, the
largest users of wastewater as they live close to cities (Amerasinghe et al., 2013). Such practices
thrive because of the markets that promise sustainable livelihood opportunities, thus making
them important links in the supply chain.
Urban growth places increasing demand on available water resources. Many cities in India are
drawing upon water supplies from hundreds of kilometres away to meet the growing needs of the
urban population (Celio and Giordano 2007; Celio et al., 2010). As the demand for water
increases, so has the generation of wastewater. Amerasinghe et al. (2012) analysed the
availability of urban wastewater for selected Indian cities, and the potential for irrigation of
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urban and peri-urban areas. This analysis showed that over 1 million hectares could be irrigated,
if wastewater is rendered safe to be used in agriculture (Carr and Blumenthal, 2004; WHO,
2006). With the population in Indian cities projected to increase by 750 million in the next 35
years, there is growing concern, however, that more and more untreated wastewater will reach
waterways, given that only 35% of wastewater is currently treated (CPCB, 2009; CSE, 2012;
Amerasinghe et al., 2012). Virtually oblivious to the quality of the water, peri-urban farmers
continue to use the wastewater that is freely available to them, even as far as 80 km downstream.
While it is well known that some degree of water purification takes place as water is transported
along the length of the watercourses, through processes such as sedimentation and
biodegradation (Lefebvre et al., 2004; Ensink et al., 2010), it is also common for new inlets of
storm water flows to re-contaminate these waters.
Wastewater is an important resource for farmers and the use of untreated or partially treated
wastewater for irrigation can have many consequences. Some of them are, soil salinization is
already a problem that has been documented (Biggs and Jiang, 2009 and McCartney et al.,
2008), groundwater contamination with nitrates and microbes (Amerasinghe et al., 2009), the
ecosystem itself gets disrupted because of weathering and chemical reactions with reactive
species and health risks due to the contamination of crops with heavy metals and pathogens. On
the wastewater irrigation associated health risks and the presence of source water contaminants
have been documented, and the epidemiological studies shows that the direct consequences of
wastewater use are mostly linked to diarrheal diseases (Drechsel et al., 2010). Health risks
associated with heavy metals may manifest over a longer period of time, and such follow-up
studies are few and far between.
5
Previously, several authors carried out different integrated approaches for watershed scale
assessments to address a range of issues. Dhakate et al., 2013 used integrated studies for
developing the rainwater structures for groundwater augmentation; Rahm et al., 2013 for
performing integrated watershed scale assessments for sustaining wastewater infrastructure and
also Curtis et al., 2005 attempted the integrated socio-economic and biophysical approach to
improve the efficacy of watershed management.
The present study presents an integrated approach for assessing the watershed dynamics
influenced by wastewater from the Musi River. The present paper specifically focuses on the
integration of land-use pattern changes, hydrology, biophysical parameters, socio-economic
aspects, farmer perceptions, land-use suitability for agriculture and challenges in potential
irrigated area development for watershed dynamics assessment, in the face of rapid urbanization.
Such assessments would be useful for urban/peri-urban planners and policy makers.
2. Methods and data
2.1. Study area
Hyderabad (17.3660° N, 78.4760° E) is one of the fastest-growing megacities in India, and the
city has grown rapidly from 1.1 million in 1950 to over 7 million people in 2011. The city is
divided into north and south by the Musi River, which receives storm water runoff via 19
constructed nalas (constructed wastewater drains). The built-up area in 1880 was only 55 km2.
The area has expanded since, to 675 km2 following a concentric growth pattern, with a more
spread-out development being observed on the northern side of the river. Increasing water flows
are a reflection of the water that is lifted for domestic use (Fig. 1), which is 1,545 mld, at present,
and the consequent wastewater generation of over 1,000 mld (NRCD, 2001; Van Rooijen et al.,
6
2005: Amerasinghe et al., 2012). It can be assumed that the water leaving the city is a mixture of
untreated (~ 55%) and partially treated water (~45%), as three sewage treatment plants (STPs)
(Starkl et al., 2013) release the treated water from the drainage points of the city. Fig. 1 shows a
schematic diagram of surface water and wastewater flows in urban and peri-urban systems of
Hyderabad along the Musi River. To understand the origin of the wastewater from the city, Fig.
2 illustrates the urban wastewater infrastructure including interception and diversion nalas and
structures, sewage treatment plants, urban lakes or tanks and associated drainage network and
also weirs on the Musi River and associated canal network.
The focus of this study is a micro-watershed (270 ha), within the Kachivani Singaram (KS)
village, in the peri-urban area of the Musi River catchment. This type of micro-watershed can be
representative of areas in other growing cities and can be useful for planners for development
and investment. The irrigation water in the micro-watershed is a mixture of canal water arising
from the Musi River and groundwater, based on the access and availability of the type of water
(Perrin et al., 2011). The KS micro-watershed location in relation to the Hyderabad city and
digital elevation model of the study area is shown in Fig. 3. Agriculture practices in the site
comprised a multi-cropping system with paddy rice (Oryza sativa L.), paragrass (Urochloa
mutica L.) and leafy vegetables (Jacobi, 2009) where paragrass and vegetables are grown
throughout the year whereas paddy rice is grown only during two cropping seasons.
The average annual rainfall in the region in the study area is about 750 mm and rainfall occurs
mainly during the monsoon season from June to September and of semi-arid condition. The
mean annual temperature is about 27 °C, although during summer time the maximum
temperature can reach up to 45 °C. The study area is situated in an area where the basement is
made of orthogneissic granite with granite, quartz and dolerite intrusions. The hydrogeological
7
boundary of the study area encompasses the surface watershed limit and extends northwards to
an extensive dolerite dyke. Because of the long-term weathering processes, a typical weathering
profile in granitic terrain (Dewandel et al., 2008) is with saprolite (clayey-sandy formation with a
significant porosity but quite low permeability) layer (10-15 m thick), mainly subhorizontal and
with some subvertical fissures partially filled up by clayey minerals, fissured layer (horizontal
fissuring network , constitutes the main transmissive zone of the aquifer) (15-20 m) and the
fresh basement where granite is unfissured (Perrin et al., 2011) (Fig. 4). In the western part of the
watershed with significant intrusions of leucocratic granites, doleritic material and
quartz/pegmatite veins constitute as the main observed outcrops (Ahmed et al., 2014). Granite
constitutes as the main lithology with small and large quartz veins are observed at different
depths. The study area is with unconfined crystalline hard rock aquifers (CGWB, 2007). The
aquifer material consists of the fractured and weathered layer of the crystalline bedrock and the
hydrogeological properties of the aquifer material in hard rock aquifers are usually
heterogeneous. In the study area large share of the aquifer recharge contributed by year round
cultivation, which generates large return flows from irrigated fields (Dewandel et al., 2008 and
Perrin et al., 2011).
It can be reliably assumed that most of the farmers in the peri-urban areas of Hyderabad use
untreated and partially treated wastewater for irrigation. The Musi River irrigation system, which
can be considered as a medium-sized irrigation project, distributes the river water via a system of
weirs and associated canals along the length of the river. The Musi River has over 22 weirs (Fig.
2), impounding the water to be channelized into canals for irrigation purposes (Ensink, et al.,
2010). The micro catchment receives irrigation water at the 1st weir, 15 km downstream of
Hyderabad city, via a channel that extends over several kilometres. The water to the agricultural
8
areas is supplied by the irrigation canal through gravitational flows and/or pumps. The system
comprises a unique system of underground pipes, and storage structures complemented by motor
pumps, to lift water 1-2 km from the source. For instance, the low-lying fields are irrigated using
gravity flows and sites further away by lifting water using pumps. Some also utilize structures
similar to wells (also called refill storage structures) that are secondary storage spaces for lifting
the water to distant locations. These are engineered structures that were built in specific places to
store water from the irrigation canals. The construction of storage structures was carried out with
government support and by clusters of farmers who benefited from the water source. Those who
do not have access to canal water or not interested in using the wastewater, used groundwater
from bore wells or dug wells for cultivation.
2.2. Integrated assessments
An integrated assessment of natural resources, social factors and economic factors at the
watershed scale is required for sustainable management of watersheds and the communities they
support (Curtis et al., 2005; Dhakate et al., 2013 and Rahm et al., 2013). A conceptual
framework for assessing the watershed dynamics is illustrated in Fig. 5. The integrated
assessment comprised land use change, annual water abstractions, harvesting potential, land use
suitability analysis, socio-economic assessments and farmer perceptions on water quality and
wastewater irrigated agriculture.
In natural homogeneous environments the evolution of land cover changes is slow and in
equilibrium state, however, in anthropogenically stressed ecosystems, habitats are altered at an
artificially accelerated rate. Firstly, micro level land use changes (detailed mapping with high
resolution datasets) were assessed using digital globe satellite data from Google Earth over the
9
last decade (datasets used: May 27, 2000 and May 5, 2010), and for the year 2010 validated by
ground truth data collection, field observations and farmers interviews and for the year 2000
validated through farmers interviews. The spatial resolution of imagery in the Google Earth is
typically higher than that of the free satellite imagery available like Landsat, MODIS etc. (Taylor
and Lovell, 2012). In general, base resolution in Google Earth is 15 m with WGS84 datum and
many areas around the world the resolution varies up to 1 m with the availability of the satellite
data. Google Earth imagery of Digital Globe satellite data used in the present study site is of with
0.65 m panchromatic and 2.5 m multispectral at nadir. The processing of the images was done
with image interpretation, manual extraction and classification of different land uses from high
resolution images of the Google Earth. Based on the appearance, texture and color the built-up
and agricultural areas in the aerial images were classified and further crop wise land use
classification was done relatively in the photointerpretation. After the completion of digitization
of different land use classes in Google Earth, all the sites were re-examined to ensure the land
use class identification and size. The digitized polygons and orthorectified imagery of watershed
from Google Earth are imported to ArcGIS 9.3 platform for calculation of the area (Taylor and
Lovell, 2012). The data covering the study area were used to address the spatial variability in
cropping pattern and other land cover classes. The datasets were geo-referenced with UTM
projection and WGS 84 datum. The datasets on cropping pattern, built-up area, topographical
maps, ground truth data and farmers interviews were used as inputs for classification and
accuracy assessment. Secondly, irrigation infrastructure was mapped from field observations and
farmers interviews.
By assessing the variability in land use and irrigation practices of the distinct agricultural fields,
annual water abstractions were calculated from field measurements in the agricultural fields of
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the study area with distinct type of crops over a period of time or season. Characterization of the
hydro-geomorphology of the watershed area using geomorphological data from the National
Remote Sensing Centre’s (NRSC) Water Resources Information System (http://www.indiawris.nrsc.gov.in/). The same datasets were used to calculate the groundwater potential for each
geomorphic layer together with field observations and NRSC data. The same data set, recharge
conditions of the area and groundwater use was used to determine the potential groundwater
resource availability for agricultural development in the study area. Each of these datasets were
then used to assess the irrigation potential of wastewater and groundwater in the watershed.
Annual water abstractions were calculated for each crop and its corresponding water type per
each season using field measurement data; discharge of the lift irrigation pumps and groundwater
bore wells, pipelines and agricultural ditches, length of irrigation per day in each season and
length of cropping in each season. The principle cropping seasons in the study area are Khariff
(June to October), Rabi (November to March) and Zaid (April to May). Paddy rice is grown only
in the Khariff and Rabi seasons in the study area and the number of cropping days was
considered as 120 days. On the other hand, paragrass is a perennial crop, and therefore, all three
seasons were considered for annual water abstraction calculations. Vegetable farmers grow six to
eight crops per year irrespective of the season and was considered as a perennial crop like
paragrass.
Various biophysical, social and economic factors are considered for watershed scale suitability
analysis, as these are important not only for local farmers but decision making officials as well,
in understanding the watershed impact factors. We designed a framework for assessing the land
for agriculture irrigation suitability using a number of attributes. The suitability analysis was
adapted from Steiner et al. 2000 for the Gila River watershed in Arizona and New Mexico,
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which utilised a series of matrices that evaluated the biophysical and socio-economic factors
against a number of other attributes like land use needs. In the study, a series of matrices were
used, and each matrix comprised two sets of factors plotted against each other. These were the
general land use needs and the special attributes of the micro-watershed. The land suitability
matrix is a collection of both suitable and unsuitable relationships between categorical factors
and land-use needs. The matrix helps in identifying desirable areas and opportunities for
agricultural land use. This suitability analysis was designed considering all the possible impact
factors (land attributes, hydrology, etc) for an integrated assessment of a peri-urban watershed,
and allows to create a holistic view useful to decision makers.
Forty-seven farmers, who were using wastewater or groundwater, were interviewed to respond to
the recent efforts made by the government to reduce pollution reaching the river, and the use of
wastewater in crop production in and around the KS micro-watershed using a structured
questionnaire, to assess the peri-urban watershed dynamics, socio-economic factors for
development, crop choices and farmer perceptions on wastewater use for agriculture. Key topics
covered in the questionnaire were the crop choice of the farmer, their interest to pay for cleaner
water, awareness of nutrient availability in irrigation waters, perception on water quality, health
problems, socio-economic status, costs and benefits associated with wastewater irrigation, and
institutional support provided for agriculture.
3. Results
3.1. Changes in land-use patterns and irrigation infrastructure
Changes in land-use patterns at years 2000 and 2010 are shown in Table 1 and Fig. 6. Two
categories of land use were compared: the built-up area/area under development and irrigated
12
agriculture area. The built-up area increased from 14.65 ha to 29.64 ha with a change of 102%,
and the area under development increased by 142%, which is a clear indication of the rapid
urbanization of Hyderabad city in recent years. Although it is perceived that the land area under
cultivation is decreasing, the total irrigated area of the study site did not change appreciably,
during the period 2000 to 2010 (a reduction of only 1% of the total irrigated area). A notable
increase in the area under groundwater irrigation is partly attributed to the establishment of new
plots of previously barren land. The shift is a direct consequence of urban pressures, where
existing irrigated areas are being converted to commercial or housing plots and new peri-urban
areas to agricultural plots. The area under paragrass cultivation within the KS micro-watershed
reduced slightly, as did the area under paddy rice, although not significantly (Table 1). The
current preference of the farmers is growing leafy vegetables and paragrass, as it fetches a high
price in the close by markets. However, some farmers still practiced paddy cultivation to meet
the household needs. The declining preference for paddy rice cultivation appears to be due to
increased labour costs, unavailability of labour during the growing season and low yields.
Quality of rice and low yields were attributed to the poor quality of water (Biggs and Jiang,
2009), and farmers have responded to this by planting seedlings in groundwater prior to
transplantation in wastewater-irrigated fields. This exemplifies the adaptive responses of farmers
to changes in their environment.
The study showed that farmers adapted to local situations and designed the course of the
irrigation infrastructure to maximise the use of natural resources. The changes in irrigation
infrastructure between the years 2000 and 2010 are shown in Fig. 7. The storage structures were
not present in 2000 and were constructed as a means to control the sediment flow through the
pumps to their fields. The unintended benefit was that it acted like a primary treatment system.
13
3.2.
Water use, annual water abstractions, hydro-geomorphic setting and potential
water resource availability for agricultural development
The spatial maps on the types of water used for agriculture, in 2000 and 2010 are given in Fig. 7.
The observed trends where that the wastewater irrigated area had reduced marginally, from 79%
to 74% in 2010, whereas the groundwater irrigated area had increased (Table 1). Paragrass
cultivation was predominantly under wastewater irrigation, with only a few exceptions. For
instance, in 2000, groundwater was not used for paragrass cultivation, but the demand from the
dairy industry appears to have influenced the change in practice, as observed in 2010. Paddy rice
irrigation with wastewater was more in 2000 compared to 2010. On the contrary, wastewater
irrigated vegetable cultivation had increased by 2010. All the farmers between the canal and
Musi River used wastewater only for irrigation.
Annual water abstractions calculated for 2010, with respect to each crop and water type are
shown in Fig. 8. In the watershed, 70% of water use for irrigation is wastewater, and the
remaining 30% groundwater. Paddy rice was cultivated both with wastewater and groundwater,
as were the other crops. Highest wastewater use was for paragrass (68% of total wastewater
irrigation) followed by rice (28%) and only 4% for vegetables. In contrast, paddy rice was
grown mostly with groundwater (74% of total groundwater irrigation), followed by paragrass
(16%) and vegetables (10%). Approximately 40% of the water withdrawn accounted as return
flows (Perrin et al., 2011). Because of the high amount of irrigation, the return flows from paddy
rice and paragrass irrigated areas are also high (Fig. 8).
Hydro-geomorphic layers of the watershed mapped using NRSC data are shown in Fig. 9,
together with the groundwater prospects. The micro-watershed area is situated on a complex hard
14
rock aquifer system. In the northern part, which comprises the pediment (i.e. gently sloping
smooth surface of erosional bedrock with thin veneer of detritus; Babar., 2005) zone, the yield
range of wells was very low (30 - 40 m3/day). This is also a heavily built-up area and perhaps
further exacerbates the problems with overabstraction of groundwater. In the shallow and
moderate pediplain (pediplains are relatively flat rock surfaces formed by the joining of several
pediments and lithologically shallow pediplain is with sedimentary outcrops and moderate
pediplain is with metamorphic outcrops; Babar., 2005; Rai et al., 2005) zones the yield range,
homogeneity and success rate of wells is moderate. The pediplain under canal command and
shallow floodplain zones have good well yields and very high potential for groundwater
abstraction. It was observed that these two zones were already under wastewater irrigation. In the
northern part of the micro-watershed that had low groundwater potential zones, extensive
development was underway, with fences demarcating the plots owned by individual owners. The
shallow pediplain and moderate zones were already under groundwater irrigation. The potential
groundwater resource availability in these two zones was moderate and suitable for irrigation.
The total potential groundwater resource availability for agricultural development varied from
north to south and was influenced by wastewater irrigation. While the potential wastewater
availability for agricultural development in the watershed was good, lifting the water from the
canal to the northern part of the watershed was a constraint. Overall, the potential water
availability for agricultural development was “good” with wastewater and varied from “low to
high” with groundwater across the geomorphological terrain of the KS micro-watershed (Fig. 9).
3.3. Farmers perceptions
15
Farmers who were experiencing the effects of urbanization were all part of the Musi irrigation
scheme. Some were long-term residents and others were from nearby states, who had come in
search of work. A large proportion of them were women who engaged in leafy green vegetable
cultivation, and contributed to the family income. Interviewed farmer distribution with respect to
gender, age, education and farm size is shown in Table 2. The farmers felt that the water quality
appears to have improved overtime, with the installation of three new STPs and firmer adoption
of regulations related to solid waste management. While the irrigation department is in control of
releasing the water into the channels, maintaining irrigation water quality however, was not
considered as being important. There were no water user organizations that represented farmers.
Of the 47 farmers that were interviewed (Table 3), eight were groundwater users, one used both
wastewater and groundwater, and the others depended on the canal water.
The farmer’s choice of crops was mainly dependent on the land area available, irrigation water
quality and the proximity to urban markets. They indicated that, of the vegetable varieties, leafy
vegetables were the most popular and profitable, especially when wastewater was used for
cultivation. In the past, paddy rice was the crop of choice on the Musi banks. However, the
preference has changed drastically with changing water quality (Table 4). The field observations
and information provided by farmers revealed that paragrass was mostly grown using wastewater
because of the quick returns on low investments and less dependency on labour. The shift from
paddy rice cultivation to paragrass was also influenced by a booming dairy industry in the city.
All in all, several factors appear to have influenced the changes in cropping patterns, and based
on farmer remarks, these could be arranged in descending order as follows; labour costs,
unavailability of labour, demand for dairy industry, low rice yields, water quality and low quality
of rice.
16
Farmers felt that the soil quality had changed over time due to the influence of wastewater
irrigation, and corroborated by the research studies of Biggs and Jiang (2009). According to
them, the saline conditions has affected the paddy crops more than the other crops, and have led
to low productivity and quality of the rice grains. While the vegetative growth increases rapidly
during the first few months, neither the yield nor the quality is comparable to rice grown with
freshwater. As a result, they feel that the traditional crop, which was paddy in these areas, is no
longer profitable.
Most of the farmers think that further pre-treatment of wastewater is required before using it for
irrigation purposes. Farmers mentioned that they are willing to pay small amounts, which is
around INR 100 - 200 per year, if cleaner water is provided for irrigation. They also felt that they
might change the crop choices, which will provide high profits, or revert back to paddy
cultivation.
The farmers were aware of the nutrient availability in the wastewater, through experience in
cultivation. They acknowledged that they were not using fertilizer/chemical inputs, because the
availability of nutrients in the wastewater was favourable for crop growth. Farmers cultivating
paragrass were happy with the nutrient content in the wastewater, because it led to faster growth
and high yields. Farmers cultivating paddy rice, on the other hand, were not sure if the low yields
were due to excessive nutrient availability or toxicity (other chemicals) of urban wastewater
(Table 4), and no detailed studies have been undertaken to explain the field observations, so far.
Although the major nutrients N, P and K were elevated in the water sources, its bioavailability
has not been studied. Farmers complained of the foul smell and appearance (black colour) of the
Musi River water, but accepted it as a trade-off for nutrient content and were willing to continue
to utilize it because they could get good economic returns. In order to understand their
17
perceptions on the water quality, the response was graded as either ‘bad’, ‘average’ or ‘good’.
Most of the farmers stated that irrigation water quality was average or good, based on a trade-off
basis. Farmers, whose perception on water quality was good, were referring to the nutrients
already available in the wastewater, and they were confident that the water has good potential for
irrigation. As for toxic chemicals, no concerns were raised by any of the farmers who were
interviewed. While the farmers using groundwater were happy with the water they were using, it
is possible that some of the groundwater was influenced by years of wastewater irrigation in the
area and seepage from the river (Perrin et al., 2011). Most of the farmers using groundwater were
of the opinion that the quality of wastewater in the canal was not appropriate for crop production.
Two studies in the area also revealed that long periods of wastewater irrigation has affected the
soil salinity (Biggs and Jiang, 2009 and McCartney et al., 2008), and salinity was above the
permissible levels in some of the crops grown in this area. It is known that crop yields are
affected by high salinity conditions, and further studies are required to establish more suitable
crops for such environments.
While the wastewater is available year round and the quality of the water is not suitable for
vegetable production within the city limits. Further, downstream of the Musi, the soils had
elevated levels of some of the contaminants, however, the crops were not carrying hazardous
elements that were harmful to the humans (Amerasinghe et al., 2009). High salinity and ground
water contamination have also been reported by studies carried out in the same study site (Ensink
et al., 2010 and Perrin et al., 2011).
In the field observations, it was noted that most of the farmers using wastewater for irrigation
were not using any safety measures while engaging in irrigation practices. These farmers
informed that they were afflicted with skin problems, mostly itching and skin rashes on the parts
18
of the body that were exposed to wastewater. Similar responses were cited in the studies of
Ensink et al., 2010. Another common complaint was the nuisance factor associated with
mosquitoes in the paragrass growing areas. The farmers were of the opinion that the frequent
fevers that families suffered were due to the high mosquito biting rates. However, there is no
scientific evidence to support this perception. However, such health problems were considered to
be the key disadvantages working with wastewater. Srinivasan and Reddy, 2009 reported that
farmers living close to the river were more likely to be affected by health issues than those using
groundwater. Two separate studies on health risks showed that worm infection rates were
different in the populations living close to the river. For instance, Ensink et al. (2010) reported
high hook worm infections among farmers using wastewater and another study cited that the
worm infections on average were low (Amerasinghe et al., 2009). Microbial contamination in
leafy vegetables can be a health risk especially if they are eaten raw. Therefore, appropriate
wastewater treatment and awareness building on safe use are important aspects to be considered.
Van Rooijen et al., (2010) and Drechsel et al., (2010) suggested that mitigating potential urban
health risks will allow urban water managers to build benefits from the existing wastewater
reuse, which will contribute to food security while reducing the demand for freshwater for
agriculture.
The farmers reported that institutional support was non-existent for agricultural activities in the
peri-urban areas. Although the water user associations (WUAs) are very strong in many other
places in the state of Andhra Pradesh (AP), we did not find evidence of their presence within the
study site. Farmers said that they did not have to pay for the water they used. Further, the
electricity used for lifting water was free of charge for farmers in the region. Private
nongovernmental organizations (NGOs) were also not present with any activities that would
19
support the farming communities. However, the farmers were pleased with the free power supply
that was available for seven hours per day, for agricultural purposes, which enabled the operation
of the motor pumps.
Labour is a critical factor for labour-intensive crops such as paddy rice and vegetables.
Availability and costs of labour have become prohibitive, unless family labour is available.
Paragrass cultivation requires less labour effort and monitoring, and there is a high demand for it
from the dairy industry. Thus, switching from paddy rice to paragrass cultivation appears to have
taken place, under multiple drivers and pressures. With the city’s demand for vegetables, the
cultivation of leafy vegetables has become more profitable than paddy rice cultivation and is also
a strong reason for shifting to vegetable cultivation. In the farming families, more women than
men are involved in farming leafy vegetables with wastewater, thus making an important
contribution to the household economy.
4. Discussion
4.1. Socio-economic evaluation
In this small peri-urban watershed, farmers could be categorised into several types. Some owned
their land and hired labour to cultivate the land, and others leased the land and cultivated it
communally. The land sizes were small, ranging from 0.1 to 1.0 ha. The cultivation costs and
value of produce provided by the farmers were quite different for groundwater and wastewater
irrigated systems (Table 5). Although the area under vegetables was less than the areas under
paragrass and paddy rice, vegetable cultivation with wastewater produced the best profit margins
and is reflected in the profits made per annum. The quick and high profits enjoyed by farmers
were attributed to the short duration of vegetable crops, low input costs and year-round
20
cultivation. Farmers also specified that the leaf area and weight of the leafy vegetables were
greater than that of the groundwater-irrigated leafy vegetables, and were of the opinion that it
contributed to the increased total yield. For wastewater irrigated paragrass, the cultivation costs
were very low (labour costs only). Conversely, farmers using groundwater were burdened with
an additional cost of fertilizer. Despite the extra cost, some farmers felt that it was more
profitable than growing paddy rice.
It was apparent that the farmers using groundwater to cultivate paddy rice were getting higher
yields and profits (Table 5) compared to those using wastewater. While the change over from
paddy to paragrass has been gradual, a few farmers continue to grow paddy rice with wastewater
and use it primarily for home consumption. Most of the farmers cultivating paragrass own their
land; if leased, the cost was INR 30,000 to 59,000/hectare/year. The rates varied depending on
the accessibility to plots from the main road; INR 2,500 per ha if it was further away from main
road and INR 5,000 per ha if it was closer to the main road. Paragrass was sold at markets at INR
2.50 to 4.50 for a small bundle (around 5 kg) and INR 5 to 7.5 for a big bundle (around 10 kg).
In general, the paragrass was transported and sold at the fodder market in the city.
Pesticide use for paddy rice and vegetables were rampant among both groups of farmers. We
found that organophosphorous and carbamate groups of pesticides were being used throughout
the year. However, only the groundwater farmers used organophosphorous-based pesticides, and
the reasons for this was not investigated. Occasionally, they resorted to using mosquito repellent
powder in the WW paragrass fields, to control the mosquito nuisance in the area. When
wastewater was used for paragrass cultivation, fertiliser and pesticides were not used, therefore,
their nutrient and pesticide input costs were zero. Also, farmers who used wastewater for
irrigation of vegetables, spent less on nutrient supplies compared to the GW vegetable farmers in
21
the study area. But, overall, the total cultivation costs were very low for both groups. Currently,
growing vegetables in KS is considered to be highly profitable (Table 5), as there is high demand
from the urban centre.
4.2. Land-use suitability for agriculture
Integrating socio-economic and biophysical data to promote collaborative watershed
management practices is important, to bring in the different sectors into the development agenda.
Further, assessing the land suitability for economic development can further support the overall
watershed management. It also helps to identify where the future development can take place for
investment. In this study we attempted to assess the land-use suitability for agriculture and
irrigation in terms of availability of the land for agriculture, potential for future development,
possible environmental impacts and livelihood opportunities, using a watershed suitability
analysis framework (Steiner et al., 2000). An ecological inventory of the watershed combined
with biophysical and socio-economic factors showed that land suitability for agriculture was
positive, and the available peri-urban space can be potentially used for cultivation (Fig. 10). This
land-use suitability framework looks at the future land use for agriculture, thus useful for a
decision maker to look at the different options for development. Suitable or unsuitable
relationship refers to the possibility of agriculture being practised or not under the given
combinations in the matrix. Comparing with other land-use needs and multiple factors that will
determine the effective practice of agriculture, suitable (solid black dot), unsuitable (solid grey
dot) and no relationship (no colour dot) matrix gives an overall relationship with agriculture,
other land use needs and factors that influence the agriculture practice. If a relationship is
incompatible, the biophysical or socio-economic factor is either not capable of supporting or will
22
have adverse impact on the land use. The empty colour dot represents absence of a relationship.
This type of matrix that combines ecological inventory, geology and water yielding potential can
still be part of the prudent planning in urban expansion. Several constraints to agricultural
development considered are imposed due to physical or biological limitations and/or social and
economic factors restrictive for development. Economic factors include land costs and urban
development incurred by private land owners. Irrespective of geological features, soil conditions
and groundwater potential, the wastewater availability and accessibility is having good
compatibility with open spaces or barren land for agricultural area development. And also if the
barren land considered for agricultural development, the newly irrigated areas will have positive
development compatibility for biodiversity with sensitive flora and fauna. The matrix indicates
that barren land can be developed for agriculture, within the watershed, if lift irrigation is
adopted. Amongst the practices, the paragrass cultivation can be a lucrative business to support
the dairy industry, and vegetable cultivation can be safely promoted if wetlands are coupled with
the refill storage structures. Accessibility is afforded by good road connectivity, and farmers are
quite capable of finding markets for their produce as has been done in the past. Agriculture can
be a succession practice, as seen in this study, where the space that is available can be utilised
until other developmental plans take over. This analysis shows that even though the matrix has
high degrees of freedom, key points that can be gleamed from the relationships that influence the
watershed dynamics for agricultural development majorly dependent on social and economic
factors, water availability and accessibility and urban markets demand. A suitability matrix can
be a useful tool for the local level planners, where commercial development can be combined
with agriculture development. The factors that are weighted for agriculture can be superimposed
23
against other forms of development that are emerging or being planned and can form the basis
for future eco-cities.
4.3. Challenges in potential irrigated area development
An integrated approach for assessing the peri-urban watershed dynamics will answer the several
questions such as why the irrigated area has not changed much over a decade, or what are the
principle factors affecting the irrigated area development? The land use changes showed that
cropping pattern has changed from paddy rice to paragrass and vegetables, even though the total
irrigated area has remained the same. Social and economic factors explain that there is a high
demand for vegetables, but the labour availability in the peri-urban setting is becoming scarce.
The farmers were also responding to market demand for paragrass, because of the expanding
dairy industry, less man power requirement and low crop input costs. At the same time, even
though paragrass cultivation was profitable, high land prices tempted the sale of land for
commercial development. The potential groundwater resource availability was influenced by the
wastewater irrigation in the lower reaches of the watershed, however, water was never lifted
beyond 2 km, with the low cost systems that the farmers used. A good water transfer system
could easily support the upper parts of the watershed, provided safety standards and differential
uses are clearly identified. The development trajectory of the watershed appears to be from north
to south owing to a main road that links with the Hyderabad City, and the demand for water for
all types of uses will continue to grow.
5. Conclusions
24
The multiple impacts of urban development on agriculture was apparent in this peri-urban microwatershed. Land use change studies over a 10 year period revealed that, contrary to popular
perception of developers and administrators, the total irrigated area has remained more or less
the same, although the spatial distribution and boundaries of peri-urban agriculture have shifted
further afield in response to development. As the old agriculture plots were being converted to
commercial spaces, farmers were moving into other open spaces for cultivation, which has
resulted in little change to the total irrigated area. Thus, GIS studies have been useful in
visualizing changes in land use over time. The study showed that, despite development,
wastewater irrigated agriculture played an important role in the lives of a group of farmers who
derived their livelihood within the micro-watershed. Shifting cropping patterns from paddy rice
to paragrass witnessed larger areas being converted to agricultural land that required less effort to
produce. Market demand has played a key role in determining the choice of crop grown by the
farmer. The influence of the dairy industry, high labour costs and unavailability of labour have
also shaped the trends in agricultural practices that have been observed. Leafy vegetables have
become a highly profitable crop for farmers, and it is supporting the livelihood activities of many
small-scale farmers, especially women and defining new peri-urban agricultural areas. Despite
the fact that farmers using wastewater were aware of, and benefitted from, the nutrient content of
the water, they were interested in paying for good quality water because of the stigma attached to
wastewater-irrigated vegetables. The farmers complained of health issues (skin itching and
rashes etc.), but none considered it important to take safety precautions when using wastewater
for irrigation. They were also unclear if these illnesses were directly linked to wastewater, but
the perception of an association was strong in their minds.
25
The study shows the different aspects influencing peri-urban agriculture in a rapidly changing
environment around Hyderabad city. Contrary to popular perception, peri-urban farmers
continued to utilize the resources available to them, adapting to the local demands especially the
emerging markets. Therefore, it is reasonable to assume that with the year round availability of
wastewater and a good groundwater potential, peri-urban agriculture will continue into the future
as well. The integrated approach that was used to assess the dynamics of change will be useful
for policy and decision makers, to get a holistic view of impacts of development on agriculture in
peri-urban settings. It could be a key methodology for informed decision making, and to envision
peri-urban landscapes where development and agriculture can co-exist.
Acknowledgements
The authors would like to thank all the farmers who participated in the questionnaire survey, and
also the support staff at the International Water Management Institute (IWMI) for helping with
the field work. We thank in particular, Dr. K. Krishna Reddy of IWMI for his helpful
suggestions for the economic analysis. We are also thankful to the anonymous reviewers whose
reviews helped to improve the quality of the manuscript. The work was supported by the CGIAR
Research Programme on Water Land and Ecosystems (http://wle.cgiar.org).
26
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Figure captions:
Fig. 1. Schematic diagram of water flows from Hyderabad City into the Musi River.
Fig. 2 Urban wastewater and storm water infrastructure of Hyderabad city
Fig. 3. Location map of the study area; (a) Kachivani Singaram (KS) micro-watershed in relation
to Hyderabad city, (b) Digital elevation model of the study area (ASTER, 30 m).
Fig. 4 Longitudinal hydrogeological cross-section of the study area
Fig. 5. Integrated conceptual framework developed for this study to assess the watershed
dynamics.
Fig. 6. Comparative decadal change of land use and land cover maps for the years 2000 and 2010.
Fig. 7. Irrigation water use infrastructure in wastewater and groundwater irrigated areas for the
years 2000 and 2010.
Fig. 8. Crop wise annual water abstractions and return flows in the study watershed
Fig. 9. Geomorphological layers and their corresponding groundwater prospects in the study area;
WS – Watershed; Rc – Recharge conditions; AM – Aquifer material and FR – Fractured rock, FIR
– Fissured rock, WR – Weathered rock, LS – Loose sediments; HS - Homogeneity and success
rate of wells; Well yield in m3/day
Fig. 10. Land-use suitability anlysis matrix based on land use needs and, biophysical and socioeconomic factors.
32