Maharashtra SSC Water Security Grade flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Monsoon rainfall share

Roughly three-quarters of Maharashtra's annual rainfall arrives during the June-September southwest monsoon, so a single weak monsoon can sharply reduce reservoir storage and crop output.

Rain-shadow districts

Solapur, Beed, Osmanabad, Jalna and Ahmednagar lie east of the Western Ghats and receive under 700 mm annual rainfall, making them chronically drought-prone and dependent on groundwater and tankers.

Water balance equation

For a catchment, precipitation equals evapotranspiration plus runoff plus the change in storage (P = ET + Q + ΔS). It underpins irrigation planning, reservoir yield estimation and recharge assessment.

Infiltration versus percolation

Infiltration is water entering the soil surface; percolation is its downward movement through soil layers toward the water table. Compacted or bare surfaces slow both and increase surface runoff.

Runoff coefficient

The fraction of rainfall that becomes surface runoff. It rises with impervious cover, slope and rainfall intensity, and falls with vegetation cover and high infiltration capacity.

Watershed definition

A watershed is the land area draining to a common outlet, bounded by ridges. Boundaries are topographic, so they rarely coincide with village, taluka or district administrative lines.

Ridge-to-valley treatment

A watershed treatment sequence that stabilises upper ridges with vegetation and contour trenches first, then treats middle slopes and finally the valley with check dams and percolation tanks.

Percolation tank

A tank built across a small stream on permeable ground to impound rainwater so it infiltrates and recharges the aquifer. It needs a spillway and periodic desilting to stay effective.

Coliform standard

Drinking water must contain zero E. coli and zero total coliforms per 100 mL. Their presence indicates faecal contamination and immediate risk of cholera, typhoid and diarrhoeal disease.

Fluoride health effects

Fluoride above 1.0-1.5 mg/L causes dental fluorosis in children; sustained intake above 3-4 mg/L leads to skeletal fluorosis with joint pain and bone deformity.

Nitrate and blue baby syndrome

Nitrate above 45 mg/L in drinking water causes methaemoglobinaemia in infants under six months, where blood cannot carry oxygen properly. Fertiliser runoff and sewage are common sources.

BOD and COD

Biochemical oxygen demand measures oxygen consumed by microbes breaking down organic matter; chemical oxygen demand measures total oxidisable matter. Higher values indicate heavier organic pollution.

Rural service norm

Rural drinking water supply is planned at 40 litres per capita per day, urban at 135 lpcd, and livestock at 55 lpcd, with a protected source within 1.6 km in plains.

Jal Jeevan Mission

A national programme aiming to provide every rural household with a functional household tap connection delivering potable water in prescribed quantity and quality, with village-level operation and maintenance.

ODF-Plus

A sanitation status beyond open-defecation-free that requires solid and liquid waste management, faecal sludge treatment, and sustained behaviour change so toilets remain in use.

Residual chlorine

Free chlorine of about 0.2-0.5 mg/L should remain at the tap after chlorination. Too little allows bacterial regrowth; too much causes taste and odour complaints.

Crop evapotranspiration

Crop water use is estimated as ETc = ET0 × Kc, where ET0 is reference evapotranspiration from the Penman-Monteith method and Kc is the crop coefficient for the growth stage.

Drip irrigation efficiency

Drip systems deliver water to the root zone with roughly 80-90% efficiency, against 30-50% for flood irrigation, cutting water use while often raising yield and fertiliser efficiency.

Sugarcane water demand

Sugarcane consumes the largest share of irrigation water in Maharashtra. Drip with fertigation can cut its water use by 40-50% while maintaining or raising yield.

Roof rainwater potential

Harvest potential equals roof area × annual rainfall × runoff coefficient (about 0.8-0.9 for roofs). A 100 square metre roof in 1,000 mm rainfall yields roughly 80,000 litres.

First-flush diversion

Discarding the first runoff from a roof, typically the first 1-2 mm of rainfall, removes dust, bird droppings and debris before water enters the storage tank.

Check dam

A small barrier across a stream that slows flow and increases infiltration into the banks and bed. It needs a stable foundation, a spillway and desilting to prevent silt clogging.

MWRRA

The Maharashtra Water Resources Regulatory Authority sets bulk water tariffs, allocates water among sectors, and issues entitlements, with drinking water given first priority in allocation.

Maharashtra Groundwater Act

The Maharashtra Groundwater (Development and Management) Act, 2009 empowers the state to notify stressed areas and restrict new wells, deepening and groundwater use in those areas.

Water Users' Association

A WUA is a farmer body that takes over operation and maintenance of a canal distributary under Participatory Irrigation Management, collecting water charges and scheduling rotational supply.

Interstate water disputes

Maharashtra is party to the Krishna and Godavari water disputes, adjudicated by tribunals under the Inter-State River Water Disputes Act, which allocate shares among riparian states.

2005 Mumbai deluge

On 26 July 2005 Santa Cruz recorded 944 mm of rain in 24 hours, causing urban flash flooding, landslides and over 1,000 deaths, a benchmark for urban flood preparedness.

Drought types

Meteorological drought is a rainfall deficit, hydrological drought a shortfall in reservoirs and groundwater, and agricultural drought a soil-moisture deficit affecting crops. They develop in sequence.

Standardised precipitation index

SPI expresses rainfall departure from the long-term median over 1, 3, 6 or 12 months. Negative values indicate deficit; it allows drought comparison across regions and seasons.

Climate adaptation for water

Adaptation includes short-duration drought-tolerant crop varieties, shifted sowing dates, micro-irrigation, farm ponds, watershed recharge and diversification away from sugarcane, to buffer rainfall variability.

Coastal saline intrusion

Sea-level rise and heavy groundwater pumping in coastal Maharashtra draw seawater into aquifers, salinising drinking-water wells and requiring pumping limits or recharge barriers.

Village Water and Sanitation Committee

A Gram Panchayat sub-committee that plans, operates and maintains village water supply, collects tariffs, monitors source quality and promotes hygiene under the Jal Jeevan Mission.