Comprehensive Study Notes on Maharashtra River Systems

Fundamentals of River Systems and Concepts

• Definition of a River: A river is a natural water flow that originates in mountains or high-altitude areas and flows according to gravity towards lower elevations, eventually meeting a sea, lake, or another river.
• The Gravity Principle: Water never flows uphill; it always moves according to the slope. This single principle is necessary to solve $90\%$ of geography questions related to rivers.
• River Anatomy and Terminology:
  • Source (Origin): The specific location where a river begins, such as a mountain, glacier, or spring.
  • Mouth: The point where the river flows into the sea or a larger body of water.
  • Tributary (Upnadi): A smaller river or stream that joins a main river, functioning like a branch of a tree.
  • Distributary (Vitari-ka): A branch that splits off from the main river and flows away, usually found in delta regions.
  • Confluence (Sangam): The location where two or more rivers meet.
  • Basin (Catchment Area): The total land area from which a river and its tributaries collect water.
• The Three Stages of a River:
  • Youth Stage (Mountainous Phase): Characterized by very high velocity and heavy erosion. Formations include 'V' shaped valleys, waterfalls, and gorges. Construction of dams is ideal here due to narrow valleys.
  • Mature Stage (Plains Phase): Velocity is moderate, and the primary work is transport. Features include meanders (winding paths) and the formation of fertile land.
  • Old Stage (Mouth Phase): Velocity is extremely low, leading to deposition. Features include deltas and floodplains.
• Comparison of Indian River Systems:
  • Himalayan Rivers: Examples include the Ganga, Yamuna, Indus, and Brahmaputra. These are geologically "young," snow-fed, and perennial (flow year-round).
  • Peninsular Rivers: Examples include the Godavari, Krishna, Tapi, and Narmada. These are geologically "older," rain-fed, and seasonal (often dry up in summer).
• Flow Directions:
  • East-flowing Rivers: Flow into the Bay of Bengal and typically form deltas (e.g., Godavari, Krishna, Kaveri, Mahanadi).
  • West-flowing Rivers: Flow into the Arabian Sea and typically form estuaries or creeks (e.g., Narmada, Tapi, Sabarmati, Mahi, and Konkan rivers).
• Drainage Patterns:
  • Dendritic: Resembles tree branches (e.g., Godavari basin).
  • Trellis: Rivers meet at right angles, resembling a ladder (common in folded mountains).
  • Radial: Rivers flow outward from a central point like spokes on a wheel (e.g., Amarkantak, where Narmada, Son, and Mahanadi originate).
  • Rectangular: Right-angled bends due to rock fractures.
  • Centripetal: All rivers flow toward a central depression (e.g., Lonar Lake).

Physical Structure and Water Divides of Maharashtra

• Physical Divisions:
  • Konkan Coastal Strip: A narrow strip between the Arabian Sea and the Sahyadri mountains ($30$ to $50\,km$ wide, $720\,km$ long). Altitude is $0$ to $150\,m$.
  • Sahyadri (Western Ghats): A mountain range approximately $750\,km$ long in Maharashtra with heights between $900$ and $1,200\,m$. It acts as the primary water divide.
  • Maharashtra Plateau (Deccan): Covers approximately $80\%$ of the state. Altitude is $450$ to $750\,m$. It consists of basalt lava rock and slopes from West to East.
• The Sahyadri as a Water Divide: The crest line of the Sahyadri mountains separates water flowing into the Arabian Sea from water flowing toward the Bay of Bengal.
  • Area vs. Water Paradox:
    • Konkan (West): Covers only $8$ to $10\%$ of the area but receives $2,500$ to $6,000\,mm$ of rain. It holds $45\%$ of the water but has very low usability due to steep terrain and lack of flat land for dams.
    • Plateau (East): Covers $90\%$ of the area but receives only $500$ to $1,250\,mm$ of rain. It holds $55\%$ of the water but has high usability and heavy agricultural demand.
• Major Mountain Ranges and River Separation:
  • Satpura Range: Separates the Narmada and Tapi basins.
  • Satmala-Ajanta Range: Separates the Tapi and Godavari basins.
  • Harishchandra-Balaghat Range: Separates the Godavari and Bhima basins.
  • Shambhu-Mahadev Range: Separates the Bhima and Krishna basins.

The Godavari River System (Dakshin Ganga)

• Basic Data:
  • Source: Brahmagiri Mountain, Trimbakeshwar, Nashik ($1,067\,m$ altitude).
  • Total Length: $1,465\,km$.
  • Length in Maharashtra: $668\,km$.
  • Significance: Longest river in the Peninsula; 3rd longest in India. It covers nearly $49\%$ of Maharashtra's land area.
• Course in Maharashtra: Flows through 8 districts: Nashik, Ahilyanagar (Ahmednagar), Chhatrapati Sambhajinagar, Jalna, Beed, Parbhani, Nanded, and Gadchiroli.
• Tributary Systems:
  • Left-Bank (North): These contribute $84\%$ of the water. Major rivers include Purna, Pranhita, Indravati, and Sabari.
  • Right-Bank (South): These contribute $16\%$ of the water. Major rivers include Pravara, Mula, Sindphana, and Manjara.
• The Pranhita System: This is the largest tributary network of the Godavari. It is formed by the confluence of the Wardha and Wainganga rivers near Chaprala/Sironcha in Gadchiroli. The Penganga meets the Wardha before the Wardha joins the Wainganga.
• Major Dams and Projects:
  • Jayakwadi (Nath Sagar): Located in Paithan. An earthen dam approximately $10\,km$ long. Known as the lifeline of Marathwada.
  • Nandur-Madhyameshwar: Known as the "Bharatpur of Maharashtra," it is a Ramsar site and bird sanctuary.
  • Gangapur: Located in Nashik; supplies water to the city.
  • Bhandardara (Wilson Dam): One of the oldest dams ($1910$), built on the Pravara river.
  • Vishnupuri Project: Located in Nanded; one of the largest lift irrigation schemes in Asia.

Krishna and Bhima River Systems

• Krishna River Basics:
  • Source: Panchganga Temple, Mahabaleshwar, Satara ($1,337\,m$ altitude).
  • Total Length: $1,400\,km$.
  • Length in Maharashtra: Only $282\,km$, yet the basin covers $24\%$ of the state because the Bhima is a massive sub-tributary.
  • Tributaries: Koyna, Venna, Warna, Panchganga, Dudhganga, Ghataprabha, Malaprabha, and Tungabhadra.
  • Preeti Sangam: The face-to-face confluence of the Krishna and Koyna rivers at Karad (Satara).
• Bhima River Basics:
  • Source: Bhimashankar, Pune. It is one of the 12 Jyotirlingas.
  • Length: $725\,km$ (mostly in Maharashtra).
  • Chandrabhaga: The name given to the Bhima river at Pandharpur due to its half-moon shape.
  • Tributaries: Indrayani (Alandi-Dehu), Mula-Mutha (Pune), Nira, Seena, and Ghod.
• Panchganga River: A confluence of five rivers: Kasari, Kumbhi, Tulshi, Bhogawati, and the "invisible" Saraswati. It meets the Krishna at Shirol.
• Key Reservoirs:
  • Koyna (Shiv Sagar): Known as the "Fortune of Maharashtra" (Bhagyalaxmi). It is the state's largest hydroelectric project capacity ($1,960\,MW$).
  • Ujani (Yashwant Sagar): Located on the Bhima river in Solapur. It has the highest storage capacity among Maharashtra's dams.

Tapi-Purna and Narmada River Systems

• The Rift Valley Principle: These rivers flow westward because they reside in tectonic depressions (Rift Valleys) between mountain ranges.
  • Narmada: Between Vindhya and Satpura ranges.
  • Tapi: Between Satpura and Satmala-Ajanta ranges.
• Tapi River:
  • Source: Multai, Betul district, Madhya Pradesh.
  • Total Length: $724\,km$ ($208\,km$ in Maharashtra).
  • Sub-basin: The Purna (Amravati source) is the largest tributary. It flows through the "Kharpanpatta" (salty water belt) in Akola and Buldhana.
  • Dams: Hatnur (Jalna) and Girna (Nashik/Jalgaon).
• Narmada River:
  • Source: Amarkantak, Madhya Pradesh.
  • Significance: Smallest river basin in Maharashtra ($2\%$). It only touches the boundary of Nandurbar district for about $54\,km$.
  • Projects: The Sardar Sarovar Dam (Gujarat) provides electricity to Maharashtra ($27\%$ share).

Konkan River System

• General Characteristics: Rivers are short ($50$ to $150\,km$), flow with high velocity on steep gradients, and are seasonal. Most flow into estuaries (creeks) rather than forming deltas.
• Parallel Drainage: Rivers flow from the Sahyadri to the Arabian Sea in parallel lines, like railway tracks.
• Notable Rivers (North to South):
  • Ulhas: Longest river in Konkan ($145\,km$). It forms Salsette Island (where Mumbai is located) along with the Vaitarna.
  • Vaitarna: Originates in Trimbakeshwar (like Godavari) but flows west. Main water source for Mumbai.
  • Savitri: One of the five Mahabaleshwar rivers; the only major one to flow west into the Bankot creek.
  • Vashishti: Flows through Chiplun to the Dabhol creek. Site of the Enron/RGPPL power project.
  • Terekhol: Forms the southern boundary between Maharashtra and Goa.
• Mumbai Water Supply Lakes: Bhatsa (largest), Upper Vaitarna, Middle Vaitarna, Modak Sagar, Tansa, Vihar, and Tulsi.

Water Disputes and Legal Framework

• Constitutional Basis: Article $262$ empowers Parliament to adjudicate interstate river disputes. Such disputes are outside the jurisdiction of regular courts.
• Major Tribunals and Commissions:
  • Godavari Water Disputes Tribunal (GWDT): Established in $1969$ under Justice R.S. Bachawat. Settled via mutual agreements in $1979$.
  • Krishna Water Disputes Tribunal - I (KWDT-I): Established $1969$ (Bachawat), award in $1973/1976$. Water allocation ratio (Mah:Kar:AP) was approx $560:700:800\,TMC$.
  • Krishna Water Disputes Tribunal - II (KWDT-II): Established $2004$ under Justice Brijesh Kumar. Dealt with the height of the Almatti Dam (Karnataka), which causes flooding in Sangli and Kolhapur.
  • Mhadei (Mandovi) Tribunal: Established $2010$ (Justice J.M. Panchal). Goa, Karnataka, and Maharashtra allocation: approx $24:13.4:1.33\,TMC$.
• Intrastate Disputes: Jayakwadi vs. Upstream (Nashik-Ahmednagar). The Maharashtra Water Resources Regulatory Authority (MWRRA) Act of $2005$ regulates equitable distribution.
• River Linking Projects:
  • Damanganga-Pinjal: Diverting Konkan water to Mumbai for drinking.
  • Nar-Par-Girna: Diverting excess Konkan water to the Khandesh region.
  • Wainganga-Nalganga: A massive Vidarbha link ($426\,km$) from Bhandara to Buldhana.

Practice Examination and Questions

• Questions & Discussion:
  • Q1: What is the main physical factor determining river direction in Maharashtra? Ans: The Sahyadri and Satpura ranges.
  • Q2: Which is the largest river basin by area in Maharashtra? Ans: Godavari ($49\%$).
  • Q3: Which range separates the Godavari and Tapi basins? Ans: Satmala-Ajanta.
  • Q4: What is the reservoir name for the Jayakwadi project? Ans: Nath Sagar.
  • Q5: Which river is known as Chandrabhaga in Pandharpur? Ans: Bhima.
  • Q6: What does Maharashtra receive from the Sardar Sarovar project? Ans: Electricity ($27\%$ share).
  • Q7: Which Konkan river forms the border with Goa? Ans: Terekhol.
  • Q8: Explain the pattern of Amarkantak rivers. Ans: Radial pattern; rivers flow in different cardinal directions from a central origin.
  • Q9: Why don't west-flowing rivers form deltas? Ans: Because they flow through narrow rift valleys with steep slopes and high velocity, directly entering the sea.
  • Q10: What is the "Preeti Sangam"? Ans: The confluence of Krishna and Koyna at Karad.