Introduction to groundwater resources management

Introduction to groundwater resources management
Jac A.M. van der Gun , Previously employed with Deltares/TNO Netherlands Geological Survey & International Groundwater Resources Assessment Centre (IGRAC) - Introduction to groundwater resources management -

- Introduction to groundwater resources management -
Prologue: Watershed and River Basin Management: How does groundwater fit? Some distinguishing features of groundwater: 1 Spatial units: – aquifers rather than river basins – other horizontal and vertical boundaries 2 Time scales of processes are different 3 Different storage/flux ratio 4 Less open to observation 5 Different interaction with people - Introduction to groundwater resources management -

Jac A.M. van der Gun 1 Introduction 2 Basic concepts and supporting subjects (shortened) 3 Water resources plan development (shortened) 4 Groundwater resources management issues 5 Implementing groundwater resources management 6 Case studies - Introduction to groundwater resources management -

Chapter 1: Introduction
Role of water in human society (and beyond) Complicating factors regarding water resources Water resources management - Introduction to groundwater resources management -

Water and Man Domestic use Irrigation Production/cooling water Navigation Fishery Source of energy Recreation Sewage/ wastewater disposal Flooding/ water-logging Environment and ecosystems Water is …...a biological need, …..an economic commodity, ….and an environmental factor - Introduction to groundwater resources management -

Role of groundwater - Introduction to groundwater resources management -

Groundwater abstraction
Intensity (mm/year) 70% of global abstraction is by ten countries only Purpose of use (shares of main water use sectors) - Introduction to groundwater resources management -

Groundwater abstraction
Ogalalla, USA Jeffara,Libya Evolution (in km3/yr) Strong declines of the groundwater levels - Introduction to groundwater resources management -

Competitive demands in a water scarcity environment
river system projected reservoir reservoir projected complex of irrigated lands town - Introduction to groundwater resources management -

Interdependency Traditional perception Project goal 1 Project goal 2 Project n goal n A more realistic perception Project outcome 1 Project outcome 2 Project n outcome n - Introduction to groundwater resources management -

Soil salinization in ancient Mesopatamia
Prosperous irrigation areas Steadily progressing soil salinization Reactions: - moving to new lands - fallow-land rotation - from wheat to barley Results: - general decline - diminishing crop yields - abandoned agricultural lands - Introduction to groundwater resources management -

Mechanism of soil salination
Volumes of water: R I ET rainfall irrigation evapotransp. Salt concentrations: cr ci ce Control volume of soil: (undrained) cc capillary flow C Soil salt quantity S Mean annual soil water balance: R + I + C - ET = 0 Mean annual soil salt balance: Rcr + Ici +C cc - ETce = ΔS Because ce < cr , ci,,, cc it follows: ΔS > 0 - Introduction to groundwater resources management -

It took long before the hydrological cycle was correctly understood
Theories on the origin of groundwater and springs Homeros Thales of Milete Plinius the Elder Leonardo da Vinci Johann Kepler Aristotle Seneca René Descartes Oceanus theory Condensation theory Percolation theory Vitruvius Bernard Palissy Pierre Perrault Edmund Halley Edmé Mariotte Athanasius Kircher, 1665 - Introduction to groundwater resources management -

Global population growth 1900 - 2000
- Introduction to groundwater resources management -

Changing water demands per capita
Increasing wealth: - affordability of buying water - willingness to pay for water Motivators for more water per capita: - improvement of hygiene and health - improved & controlled food production steadily developing water using industry - comfort, recreation and leasure Enabling technological development: - knowledge on water resources - water development technology - water use technical infrastructure - Introduction to groundwater resources management -

Evolution in groundwater resources development technology
Noria (saqiyah) - Introduction to groundwater resources management - shaduf

Climate change Source: IPCC, 2001 - Introduction to groundwater resources management -

Complicating factors regarding water resources
- Conflicts of interest - Interdependency of activities - Poor perception of reality / lack of data - Water is a common property resource - Water is a vulnerable resource - The world is continuously changing (local & global change) Consequently…… there is often a need for intervention - Introduction to groundwater resources management -

Water resources management: intervention objectives
Conserve and control water resources + related ecosystems and environment Provide water and maintain water functions according to requirements Maximize total benefits from the resource and allocate them optimally Minimize costs involved in water sector - Introduction to groundwater resources management -

Typical evolution in water sector activities
Time reconnaissance water resources development water resources management increasing population industrialisation higher consumption levels awareness of interdependencies - Introduction to groundwater resources management -

Groundwater resources management (GWRM) defined:
“A planned and ongoing activity to optimize the exploitation and use of regional or national groundwater resources……... ……. taking into account the sustainability of the groundwater resources and the groundwater related environment and ecosystems.” - Introduction to groundwater resources management -

Groundwater resources management in a nutshell
Problems? Opportunities? Other policy fields Monitoring Groundwater Planning Implementation Plan approval and acceptance - Introduction to groundwater resources management -

Chapter 2: Basic concepts and supporting subjects
Systems approach Groundwater systems Water demands Economics - Introduction to groundwater resources management -

Systems approach “real world” system 1 water resources system “systems” and interrelations system n - Introduction to groundwater resources management -

System operation (1) Nature of system System operation Physical laws System - Introduction to groundwater resources management -

System operation (2) System operation Output Input System - Introduction to groundwater resources management -

System operation (3) Nature of system System operation Output Input System Physical laws System - Introduction to groundwater resources management -

The hydrological cycle as a system
atmosphere vegetation land surface surface water soil groundwater oceans deep lithosphere - Introduction to groundwater resources management -

Systems approach to water resources management
Socio-economic system Present state, functions, performance, etc. Desired state, functions, performance, etc. Physical water system Decision variables State at time t System operation State at time t + Δt Uncontrollable variables - Introduction to groundwater resources management -

Some aspects of groundwater systems
Invisible resource Ratio storage/flux is large (mean residence times between 10 and 1,000 yrs are common) Common pool & open access resource Many functions Schematization - Introduction to groundwater resources management -

Functions of groundwater systems
More than a source of water only ….. “sustained yield” reservoir “mining” reservoir reservoir for artificial recharge conduit for water transmission energy absorber (pumping) source of energy (geothermal energy) reservoir for seasonal heat storage water quality modifyer control of base flow and springs water supply to phreatophytes/wetlands control of land subsidence - Introduction to groundwater resources management -

Groundwater in a “lumped system” schematization
Direct recharge Diffuse discharge Recharge from streams, lakes, etc. Spring flow & discharge to streams, lakes, etc. Artificial recharge Abstraction Subsurface inflow Subsurface outflow Groundwater system (stored volume, water quality, average head, etc.) - Introduction to groundwater resources management -

Distributed groundwater systems
(1) hydraulic schematization aquifer aquitard Aquitard/aquiclude (2) flow systems schematization - Introduction to groundwater resources management -

Water demands Quantity: Quality:
Domestic: total and per capita demands Irrigation: irrigation requirements, leaching requirements Industry: process water, cooling water demands Environment /nature: desired/ minimum/ maximum groundwater level Quality: Standards for drinking water quality Idem for irrigation, industry, environment, nature Aspects: chemical, bacteriological, physical (incl. sediments) It is important to know what impacts violating any of the requirements or standards will have - Introduction to groundwater resources management -

Role of economics in water resources management
Comparing economic merits (scores) of alternatives or strategies Defining economic optima: Maxx Profit = (ΣR-ΣC) Understanding or predicting people’s behaviour - Introduction to groundwater resources management -

Conventional economic theory ignores market failures
Missing markets Poorly defined ownership or user rights External benefits External costs (disbenefits) Unequitable allocation of benefits/costs Lack of intergenerational equity Environmental and sustainability problems Market failures are triggers for government interventions - Introduction to groundwater resources management -

Natural resources Characterised by “stock” (reserves) and “flow” (quantities transfered per unit of time) Examples: solar energy Important distinction: - perennial resources - renewable resources - exhaustible or mining resources water, fish, forests, etc oil and gas, mineral ores - Introduction to groundwater resources management -

Optimal exploitation of natural resources
Dilemma: Exploit ‘stock’ - or exploit ‘flow’ - or both? Different views, criteria and priorities: e.g.: Presence/absence of substituting resources Economic optimization Sustainable development Poverty alleviation Protection of ecosystems Self-supporting food production - Introduction to groundwater resources management -

Economically optimal exploitation of natural resources
Dilemma: Exploit ‘stock’ - or exploit ‘flow’ - or both? Economic optimization: Given : S = stock of natural resource b = input of natural resource a = input of other production factors G = growth function of natural resource V = value of discounted profits π = profit function Then the optimum follows from: subject to: - Introduction to groundwater resources management -

Set of equations for natural resources management
(1) “Maximum Principle” (2) Portfolio balance equation (3) Dynamic constraint Production output oriented Resources use oriented Continuity equation Note: x is envisaged production output - Introduction to groundwater resources management -

Jac A.M. van der Gun 1 Introduction 2 Basic concepts and supporting subjects 3 Water resources plan development 4 Groundwater resources management issues 5 Implementing groundwater resources management 6 Case studies - Introduction to groundwater resources management -

Chapter 3: Water resources policy and plan development
Basic aspects Outline and elements of water resources management planning Models used for groundwater resources management planning ‘Open’ or ‘interactive’ plan development - Introduction to groundwater resources management -

Difference between policies and plans
A policy encompasses in general terms the objectives, priorities and the line of actions opted for A plan translates this policy into action, it facilitates communication on it among stake-holders and it enables the results to be monitored - Introduction to groundwater resources management -

What is planning? “Planning is the process that converts data and information into a decision” O. Helweg, 1985 Planning is commonly a cyclic process: the plan is intended to cover a limited period of time (planning period) and needs to be updated periodically Before starting planning: consensus needed on jurisdiction, scope, stage (hierarchical level) and on the roles of partners in the planning process - Introduction to groundwater resources management -

Hierarchical levels in water resources management
GENERAL POLICIES development scenarios objectives constraints preferences general directives AREA-SPECIFIC STRATEGIC PLANNING area-specific WRM plan feed-back IMPLEMENTATION AND MONITORING feed-back feed-back - Introduction to groundwater resources management -

Potential main partners in planning
Target group Decision makers Technical specialists - Introduction to groundwater resources management -

Framework for WRM planning
WATER RESOURCES ASSESSMENT Water resources, demands, scenario conditions, issues, etc. STRATEGIC ANALYSIS Objectives, options, strategies, measures, evaluation VIABILITY ANALYSIS Feasibility and expected acceptance PLAN APPROVAL - Introduction to groundwater resources management -

Water resources management objectives and criteria (examples)
Economic efficiency B-C, NPV Equity water allocation income from water Sustainability stock, water levels, water quality Safety no. of victims, damage - Introduction to groundwater resources management -

Decision space and feasibility
Technical feasibility Environmental feasibility Economic feasibility Financial feasibility Legal feasibility Political feasibility - Introduction to groundwater resources management -

Main types of models in WRM planning
Simulation models Optimization models Decision rules Evaluation models - Introduction to groundwater resources management -

Simulation models Differential equation Model parameters Initial conditions Boundary conditions Solution algoritm - Introduction to groundwater resources management -

Examples of differential equations for simulation models
Saturated groundwater flow Solute transport 1-D consolidation - Introduction to groundwater resources management -

Optimization models Given: decision variables x1 through xn (control variables) Then an optimization model typically consist of: (1) OBJECTIVE FUNCTION Maximize F(x1, x2 , ……….. , xn ) 2) CONSTRAINTS gi(x1, x2 , ……….. , xn ) < 0 or = 0 (j=1, 2, ….., m) If all equations are linear linear programming - Introduction to groundwater resources management -

Example: Set of equations for optimizing natural resources management
(1) “Maximum Principle” (2) Portfolio balance equation (3) Dynamic constraint Note: b = groundwater pumping rate x = envisaged production output π = profit function G(S) = growth rate of resource - Introduction to groundwater resources management -

Evaluation models Used to compare strategies or alternatives Economic models: Present Value of Discounted Cash Flows, Internal Rate of Return, etc. Multi-Criteria Decision Models (MDCM) - Introduction to groundwater resources management -

Principle of multi-objective evaluation
Alternative 1 Alternative 2 Alternative 3 Alternative 4 Evaluation Ranking: Best Worst Objective 1: Maximize PV Alt. 4 Alt. 2 Alt. 3 Alt. 1 Objective 2: Wetland conservation Alt. 2 Alt. 3 Alt. 1 Alt. 4 Multi-criteria decision methods are needed to underpin a decision - Introduction to groundwater resources management -

Dealing with uncertainty in planning
Safety factors Emergency provisions Statistical analysis Sensitivity analysis Stochastic approaches Risk analysis Additional data collection - Introduction to groundwater resources management -

‘Open’ or interactive plan development
Top-down planning (technocratic or ‘closed’) often fails: no or limited acceptance/co-operation by stakeholders Common reasons: lack of mutual understanding government-stakeholders lack of trust between parties lack of confidence in the quality of the plan unsolved conflicts of interest lack of commitment of essential partners Therefore trend towards interactive plan development, involving representation of all major stakeholders Degree of interactivity may vary Real communication is a must - Introduction to groundwater resources management -

Arnstein’s sequence of interactivity
Informing Inquiring Consulting Co-producing Delegating Self ruling - Introduction to groundwater resources management -

Techniques in IP Brochures and leaflets Press articles Radio and TV programmes Information meetings Enquiries and interviews Work shops Public hearing meetings Stakeholder comments and position statements Working groups and task forces Electronic meetings and discussion sessions etc. - Introduction to groundwater resources management -

Chapter 4: Groundwater resources management issues
Groundwater management policy and plans have to address the issues relevant for the area concerned World-wide experience is useful to help identify issues and to benefit from ideas and solutions already developed elsewhere Diagnostic analysis on relevant issues should take place in an early stage of plan development Main approaches to identify relevant issues: inference from water system characteristics communication with stakeholders - Introduction to groundwater resources management -

Main groundwater resources management issues
Water quantity management: Water quality Environmental Rate of aquifer exploitation Encouraging or restricting groundwater pumping? Allocation of scarce groundwater Conjunctive management Salinity control Pollution control Conservation of ecologically desired ‘water type’ Groundwater level control Control of land subsidence - Introduction to groundwater resources management -

Groundwater development in the Sadah aquifer, Yemen

Rate of aquifer exploitation Sadah aquifer
Rainfall: mm/year In 1983: wells Estimated recharge: M m3/year Net pumping: M m3/year 2000 m Wajid Sandstone Granitic gneisses Schists - Introduction to groundwater resources management -

Early diagnosis Sadah aquifer
Water balance: mean depletion of 42 M m3 / year Numerical model simulation: in most likely scenario there will be continuous groundwater level decline of m per year How to manage the aquifer? - Introduction to groundwater resources management -

Rate of aquifer exploitation (groundwater storage management)
grw. storage grw. level (1) (2) (3) time (1) sustainable yield (2) mining, followed by sustainable yield (3) mining, followed by exhaustion - Introduction to groundwater resources management -

Burt’s approximate decision rule
pseudo optimum slope = annual costs or revenues revenues minus direct costs adjusted profit externality due to storage depletion slope = MSY Qopt aggregate abstraction rate Q Groundwater pumping (at rate Q) from isolated aquifer Short-term profits of over-exploitation are balanced against perpetual additional pumping cost (externality) Expanding abstraction beyond mean sustainable yield (MSY) is profitable until: - Introduction to groundwater resources management -

Profit function in Burt’s rule
Production profit Portfolio profit Externalities Check whether these simplifications are acceptable for the case considered for application - Introduction to groundwater resources management -

Optimal abstraction rates Sadah aquifer according to Burt’s rule
100 grapes MSY wheat years - Introduction to groundwater resources management -

What happened actually in the Sadah area?
Gwl (m) -30 -40 -50 -60 -70 -80 Abstraction doubled from 1983 to 1995 Many dry wells Sharp increase of ground water cost Loss of irrigation profitability Small farmers gave up and migrated - Introduction to groundwater resources management -

What about the following statement?
Groundwater storage depletion (ΔS) occurs only when groundwater abstraction (A) exceeds natural groundwater recharge (R) ….. and in that case it can be calculated as follows: ΔS = A – R (all values expressed as volumes per unit of time) - Introduction to groundwater resources management -

The previous statement is wrong: “The water budget myth” (Bredehoeft et al.) Many hydrogeologists think according to the water budget myth, but their intuition is wrong Groundwater balance should include changes in recharge (ΔR), natural discharge (Q) and changes in natural discharge (ΔQ): ΔS = Outflow – Inflow = A + (Q + ΔQ) – (R + ΔR) Typical components of ΔR: induced recharge, return flows and artificial recharge. Typical components of ΔQ: reduction in spring flows, evapo(transpi)ration and baseflows (then ΔQ is negative) - Introduction to groundwater resources management -

Maximum sustainable yield
Any new abstraction is intitially fed completely by storage depletion The storage depletion – in turn – may lead to reduction of natural groundwater outflow (ΔQ) and increase of recharge (ΔR) MSY depends on how the system will adapt at the long run: MSY = - ΔQmax,final + ΔRmax, final It follows for isolated aquifers without artificial recharge: MSY ≈ R - Introduction to groundwater resources management -

Encouraging or restricting groundwater pumping?
Depends on: Water needs (quantity and water use category) State of aquifer (over- or underexploitation) Groundwater quality Environmental effects of groundwater pumping Presence/absence of alternative supplies Profitability of water use Renewable or non-renewable groundwater? Partly conflicting aspects - thus: choice based upon preferences - Introduction to groundwater resources management -

Renewable versus ‘non-renewable’ groundwater
Recharge is sufficient for realistic sustainable development Hence, the resource is exploited by virtue of its renewal Mean annual recharge typically more than 0.1 % of storage Abstraction leading to steady reduction in groundwater storage is called ‘overexploitation’ Part of abstraction exceeding maximum sustainable yield is called ‘overdraft’. Renewable grw is more common than non-renewable groundwater. Non-renewable groundwater: Recharge is insufficient for realistic sustainable development Hence, the resource is exploited by virtue of significant storage Mean annual recharge typically less than 0.1 % of storage Abstraction leads to steady reduction in groundwater storage and is called “mining” Non-renewable groundwater usually is fossil, but not all fossil groundwater is non-renewable Examples: N-African deep aquifers (NWSAS, Nubian Sandstones, etc.), Arabian Platform aquifers, Great Artesian basin. - Introduction to groundwater resources management -

Environmental impacts of exploiting ‘non-renewable’ groundwater of the NWSAS Exploitable reserves: 1280 km3 Current abstraction rate: 2.6 km3/a Reversal of flow at current diffuse discharge zones (chotts) may cause aquifer salinization - Introduction to groundwater resources management -

Great Artesian Basin: groundwater level declines and recovery
Mean aquifer recharge: around 0.45 km3/year Discharge by numerous artesian wells since 1887 Total discharge declines since 1917 Number of wells, however, kept increasing Since 1997 well capping and piping programme Aim: pressure recovery and preservation Prognosis: around km3/year saved by 2014 - Introduction to groundwater resources management -

Allocation of scarce groundwater
Among potential users: use a guiding principle (water rights, sector priority, economic optimization, etc.) zoning + assignment of functions no or very limited control (e.g. water markets) In space: negative impacts not independent of aquifer zone use simulation model or simulation-optimization uncontrolled - Introduction to groundwater resources management -

Conjunctive management of groundwater and surface water
Artificial recharge (Managed Aquifer Recharge - MAR) Watershed management (ponds, rainwater harvesting, surface water reservoirs) Baseflow replenishment Conjunctive use of groundwater and surface water - Introduction to groundwater resources management -

Examples of artificial recharge
Huge recharge dam in Oman (5 km of crest length) Sand dam in Kenya - Introduction to groundwater resources management -

Conjunctive use GRW - SW
Groundwater Demands Surface water basins sources i = 1 j = 1 k = 1 i = 2 j = 2 k = 2 i = M j = N k = L - Introduction to groundwater resources management -

Optimizing conjunctive use
Discount factor Profit from water use Cost of groundwater surface water artificial recharge - Introduction to groundwater resources management -

First step to be made is assessing occurrence and origin
Salinity control First step to be made is assessing occurrence and origin - Introduction to groundwater resources management -

Salinity control: control of upconing
Fresh groundwater Saline groundwater Upconing under a pumped well in response to decrease pressure in fresh domain Methods to prevent upconing: skimming well (creating a stable mound) scavenging well (dual pumping: saline and fresh water) - Introduction to groundwater resources management -

Salinity control: sea water intrusion
Coastal zone Sea Simultaneous outflow of fresh groundwater and intrusion of seawater Stronger fresh water flux reduces intrusion tongue Note: Climate change/sea level rise may interfere - Introduction to groundwater resources management -

Irrigation-induced soil salination
Volumes of water: R I ET rainfall irrigation evapotransp. Salt loads: Rcr Ici ETce Control volume of soil: (undrained) cc capillary flow C Soil salt quantity S Mean annual soil water balance: R + I + C - ET = 0 Mean annual soil salt balance: Rcr + Ici +C cc - ETce = ΔS Because ce < cr , ci,,, cc it follows: ΔS > 0 - Introduction to groundwater resources management -

Mechanism of soil salinity control
Volumes of water: R I ET rainfall irrigation evapotransp. Salt loads: Rcr Ici ETce Control volume of soil: (drained) Pcp percolation flow P Soil salt quantity S Long-term soil salinity control (ΔS = 0 ) for Ici  Pcp Add “leaching requirement” to crop irrigation requirement and provide for drainage as needed - Introduction to groundwater resources management -

Groundwater pollution: understanding water quality
Observe current groundwater quality Define the groundwater’s origin Define water quality of recharge water Define flow processes and patterns Identify physical chemical and bacteriological processes in the unsaturated zone Identify presence, infiltration and/or injection of contaminants Identify modifications in the saturated zone (e.g. solution, precipitation and other chemical reactions) - Introduction to groundwater resources management -

Natural groundwater quality variations are primarily related to geology Documented zones with excessive arsenic in groundwater (Smedley, 2008) Groundwater quality constraints – either observed or probably present Risk of excessive fluoride in fresh groundwater (IGRAC, 2005) - Introduction to groundwater resources management -

Variations of water quality explained by flow systems
Polluted local flow systems Connate saline water Unpolluted regional system of good water quality Unpolluted but brackish regional system - Introduction to groundwater resources management -

Summary of the processes
Atmosphere Dissolution of gases and particles Earth surface Concentration by pollution and by evapotranspiration Zone open to gasses Influence of biosphere and soils Presence of O2 and CO2 Unsaturated zone Concentration by evapotranspiration Dissolution and precipitation Ion exchange Redox reactions Adsorption Saturated zone Dissolution and precipitation Ion exchange Redox reactions Adsorption Gas generation and consumption Interaction with other water bodies Zone closed to external gasses Large residence times At depth high T and p - Introduction to groundwater resources management -

Contaminants Related to human activities, e.g.: industry traffic agriculture (fertilisers, pesticides) urban life sanitary land fills Categories of sources: point-, line- and diffuse sources Effects: toxicity and biodegradation Migration of contaminants by underground transport - Introduction to groundwater resources management -

Micro-pollutants: an emerging issue
Two main categories: Pharmaceuticals and personal care products (PPCPs) Endocrine disruptive compounds (EDCs) Origin of EDCs: steroid-based food supplements, drugs, fungicides, herbicides + various household & industrial products Mode of dissemination: sewage, landfills, manure Concentration: nano- to pico-gram level (10-9 to g/l) Effects: unknown yet, but potential capacity to interfere with hormones controlling human and animal growth and reproduction - Introduction to groundwater resources management -

Contaminant transport
Pollution source Pollution plume Important processes: Density flow Convective transport Dispersion - Introduction to groundwater resources management -

Groundwater pollution control (preventive)
Wellfield protection: Zone IIIb Zone IIIa II I Aquifer protection: control pollution at the source avoid unnecessary risky activities above/in the aquifer plan unavoidable risky activities where impacts are low use vulnerability maps and monitor pollutants - Introduction to groundwater resources management -

Dealing with pollution
Alternatives: removing and disposing polluted soil/ water in-situ remediation technical isolation hydrogeological isolation treatment of polluted water using polluted water where quality does not matter - Introduction to groundwater resources management -

Need for pollution control
Aquifer vulnerability Presence of pollutants Pollution risk Value of the resource Need for control - Introduction to groundwater resources management -

Vulnerability: questions and factors
Do these waters infiltrate and migrate easily ? Do flows of water exist to enable invasion of pollutants? Will pollutants decay? (by adsorption, desintegration or discharge) Topography Recharge Soil properties Depth to phreatic level Unsaturated zone Relation with surface water Aquifer - Introduction to groundwater resources management -

DRASTIC method for mapping vulnerability
Parameters: Depth to water table Recharge Aquifer type Soil type Topography (slope) Impact of unsaturated zone Hydraulic conductivity Scores are calculated for each parameter for each spatial unit - Introduction to groundwater resources management -

DRASTIC vulnerability index
DRASTIC index = 5TD+ 4TR + 3TA + 2TS + TT + 5TI + 3Tc Values between 26 and 220 - Introduction to groundwater resources management -

Groundwater level control
Important in zones of shallow groundwater tables: phreatophytic agriculture wetlands (“wet nature”) build-up areas Control by surface water systems or by pumping river land Drainage and subirrigation - Introduction to groundwater resources management -

The Netherlands: Groundwater level control by manipulating surface water First stage: getting dry feet by drainage Second stage: drain during wet periods, supply during dry spells (winter level, summer level) Third stage: establish ‘prefered groundwater and surface water regimes’ (GGOR or PGSR) - Introduction to groundwater resources management -

Defining GGOR or PGSR Functions Current regime Optimal Regime Target satisfied ? Start analysis Regime accepted (GGOR) Water system Measures - Introduction to groundwater resources management -

Old and new approaches Old approach: No limits to functions Evacuate surplus water as quickly as possible Provide allochtone water as needed New approach: Adapt functions to conditions Provide space to store surplus water (retention areas) Minimize supply of allochtone water - Introduction to groundwater resources management -

Land subsidence Groundwater abstraction Decreasing pore pressure Increasing effective pressure Compression of porous layers Land subsidence - Introduction to groundwater resources management -

Chapter 5: Implementing groundwater resources management
Institutional and regulatory requirements Instruments and measures Effects: prediction and monitoring How to play the game: ‘top-down’ law enforcement or a participatory approach? Crossing borders: transboundary aquifers - Introduction to groundwater resources management -

Institutional and regulatory requirements
Implementing agency (with a mandate) Legislation and regulations Groundwater management policy and plan Monitoring systems Financing mechanisms Definition of communicacion/cooperation with stakeholders (‘rules of the game’) - Introduction to groundwater resources management -

Planning effort in The Netherlands ( strategic and operational )
Above these levels there are International Agreements and EU Directives - Introduction to groundwater resources management -

Instruments and measures
Categories of measures: structural works (wells, dams, artificial recharge works, etc.) government funding/operation of facilities law/ plan enforcement (including sanctions, taxes, licenses, EIA, etc.) incentives and encouragement of good practice (incl. subsidies, water markets, privatization,etc.) Supply and demand management approaches for water quantity management - Introduction to groundwater resources management -

Measures for groundwater storage management
Due to external costs of groundwater pumping: Q opt, private > Q opt, social Corrective measures to establish “social optimum”: - restrict access (licenses) - increase private cost (taxes) - Introduction to groundwater resources management -

Groundwater licensing
Obligatory request for granting grw. user rights To be submitted to GWRM agency Basis for decision: GWRM plan Different possibilities: decision depends on known parameters (area, purpose, quantity, etc.) immediate “yes” or “no” decision depends on predicted effects: then carry out study and compare predicted effects with maximum permissible decision After granting license: monitoring - Introduction to groundwater resources management -

Obligations regarding groundwater in the province of Gelderland
Pump Abstraction capacity rate (m3/hr) (m3/ 3months) Declaring: > 1 Registering: > 35 Licensing: > - Introduction to groundwater resources management -

Groundwater tariff Tool for demand management and for recovery of external costs and management costs Tariff breakdown: Annual external cost per m3 interference between pumpers salination pollution land subsidence wetland conservation & other environmental impacts user cost (scarcety premium) Annual GWRM cost per m3 studies & planning licensing collecting taxes monitoring, etc. - Introduction to groundwater resources management -

Measures for pollution control
Pollution risk mapping Land use planning and functional zoning Prohibition of certain chemicals Regulations for handling harzardous substances and waste disposal Obligatory treatment provisions Proper sanitary waste disposal practices Monitoring Quick action in case of accidental pollution - Introduction to groundwater resources management -

Who implements the plan?
Should be decided upon in a pragmatic way, but consistent with local mandates and practices One extreme: centralised government action (‘top-down’) Other extreme: self-management by stakeholders’ WRM organisation Involvement of stakeholders usually increases succes rate Informing Inquiring Consulting Co-producing Delegating Self ruling - Introduction to groundwater resources management -

Monitoring and adjustments
Monitoring “effects” and “compliance” to be preferred over “monitoring the efforts spent” Corrective action and sanctions for violators of regulations Feed-back for plan adjustment, after comparing observed effects with predicted ones Water resources management follows planning cycles - Introduction to groundwater resources management -

Crossing borders: transboundary aquifer resources management
Aquifers: main reservoirs for subsurface storage of water and ‘highways’ for groundwater flow Many aquifers are crossed by political boundaries Potential cross-boundary interferences: changes in groundwater flows, levels, pressures, volumes and dissolved substances Invisible groundwater Very slow flow Why should we bother? Eliminating potential sources of conflict Improving the overall benefit from groundwater - Introduction to groundwater resources management -

Important international initiatives on TARM
TARM/ISARM Programme – since 1997 (IAH & UNESCO-IHP) Regional Inventories: Europe, Balkans, The Americas, Southern Africa, Caucasus/Central Asia, etc. Emerging awareness on transboundary aquifer issues Mapping Transboundary Aquifers e.g. WHYMAP’s World Map (2006) and IGRAC’s TBA World Map (2009) Regulatory & institutional efforts (e.g. ILC Draft Articles on the Law on TBA and EU Water Framework Directive) Pilot projects (e.g. Guarani, North-Western Sahara, Iullemeden) - Introduction to groundwater resources management -

318 inventoried transboundary aquifer systems - Introduction to groundwater resources management -

Law of Transboundary Aquifers
Main principles: Souvereignity of aquifer States Equitable and reasonable utilization Obligation not to cause significant harm General obligation to cooperate Bilateral and regional agreements and arrangements good neighbour-ship Present status: Draft articles approved by UN General Assembly (Resolution A/RES/63/124, December 2008) States are encouraged to consider them for water management Upgrade to legally binding framework convention desirable - Introduction to groundwater resources management -

Global priorities and favoured approaches
Global policy priorities: Millenium Development Goals Sustainable Development Transition to a Greener Economy Addressing Climate Change Favoured or emerging approaches: IWRM Adaptive management Groundwater governance Integrated subsurface management Linking water management with other types of spatially defined management (‘getting out of the water box’ ) - Introduction to groundwater resources management -

Groundwater resources management in a nutshell
Problems? Opportunities? Other policy fields Monitoring Groundwater Planning Implementation Plan approval and acceptance - Introduction to groundwater resources management -

Suggested Reading Systematic description of the world’s groundwater systems, their resources, use and management, around 300 pages + maps and pictures (expected to appear by the end of 2012) - Introduction to groundwater resources management -

... More suggested reading

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