URBAN STREAM REHABILITATION
INTRODUCTION, OBJECTIVES & IMPACTS INDICATORS OF SUCCESS THE URBEM FRAMEWORK CASE STUDIES SOCIAL APPRAISAL AESTHETICS REHABILITATION TECHNIQUES SITE MONITORING BENEFITS / IMPACTS
POST IMPLEMENTATION ASSESSMENT & INDICATORS OF SUCCESS Joachim T. Tourbier, Ines Gersdorf Jochen Schanze, Alfred Olfert Technische Universitaet Dresden Institute of Ecological and Regional Development, Dresden
Content 1 Theoretical Background 1. 1 Terms and understanding of success appraisal 1. 2 State of science and current practice 1. 3 Relation to the planning and implementation and management process 1. 4 Defining the scope for success appraisal 1. 5 Development of indicators for post implementation assessment 2 Urban River Post Implementation Assessment Method 2. 1 Existing Methods of Indicator Based Project 2. 2 Procedure for the establishment of a project specific indicator system for urban river rehabilitation 2. 3 Establishing a Monitoring plan 2. 4 Application considerations 2. 5 Framework for irregular Post Implementation Assessment 3 Description of Criteria and Indicators 3. 1 Hierarchy of Criteria and Indicators 3. 2 Criteria and Indicators of Ecology 3. 3 Criteria and Indicators of Social Well-being 3. 4 Criteria and Indicators of Economic Sustainability 10. URPIA & Indicators
1 Theoretical background 1. 1 Terms and understanding of success appraisal Scientific literature serves with various terms related to (ex-post) project appraisal with relation to success. General terms include: • Project Evaluation resp. Assessment, Post Project Appraisal (Downs and Kondolf 2002 • Post Project Evaluation (Kondolf and Micheli 1995, Kondolf 1998) • Success Appraisal or Assessment of Success (Schmickler 1986, Heitzer 2000, Scholz 2000 c, Hobbs 2003, Brühl 2004) • Effectiveness Monitoring (FISRWG 1998), Performance Control or Audit (Marti and Stutz 1993, Skinner 1999, Downs and Gregory 2004) • Environmental Impact Auditing (Glasson et. Al, 1999) etc. To delimit the attempted reach of appraisal this presentation will concentrate on the term “Post Implementation Assessment” (PIA).
• Post Implementation Assessment is an indicator based evaluation of intended and unintended effects, effectiveness and efficiency of an urban river rehabilitation effort. • In choosing the term Post Implementation Assessment respect is paid to the fact that PIA is a part of the complex project assessment. • PIA being an integral part of any rehabilitation project which is not ended until assessment results are published. • Indicators must: - be enquired at different (at least two) points of time – before and after the implementation process. - have a spatial and temporal resolution. - reflect thematic targets of the project as precise as possible.
1. 2 State of science and current practice • • • The importance of and the need for post project appraisal is well documented in scientific literature referring to river rehabilitation, to urban and spatial development and in General Post implementation assessment is not only considered important for the determination of whether and to which degree a rehabilitation project has been successful. Project appraisal itself is often seen to be a vital component of successful river rehabilitation (cf. Kondolf 1995, Bruce-Burgess and Skinner 2002). In practice only few exemplary cases of appraisal monitoring efforts are known (Marti and Stutz 1993, Hillenbrand Liebert 2001). Appraisal of social and economic impacts of river rehabilitation projects is conducted even less. Reasons mentioned are the complexity, uncertainty and related difficulties of predicting socio - economic impacts and their measurement (c. f. Diaz Redondo, 2003).
Reasons for lacking systematic project appraisal are manifold (Kondolf 1995, Kondolf and Micheli 1995, Bruce-Burgess 2001, Downs and Kondolf 2002): • Missing legal requirements to conduct appraisals and therefore • Funding usually covers only the physical part of implementation, regarding post project appraisal to be rather scientific work • Complexity of the riverine system and connected difficulties in measuring the effect • Reluctance of responsibles to be confronted with bad news • Project appraisal is often not foreseen in the project concept (Schanze et al. i. p. ) • Lack of knowledge about how to conduct appraisal • Lack of data
1. 3 Relation to the planning and implementation and management process • Based on the controlling approach used in business economics (cf. Ossadnik 2003, Brühl 2004) Scholz (2000 c) proposes the understanding of post project appraisal as part of the overall project evaluation. Control of framework conditions and premises Control of accomplishment and realisation t 0 t 1 Implementation Strategic decision Problem identification • t 3 t 2 New problem identification Control of effectiveness and impacts Control of efficiency and adequacy Figure 1: Assessment of success as a strategic process (modified from Scholz 2000 c, p. 11, Ossadnik 2003, p. 285)
• Success appraisal is to be seen embedded in the general planning, implementation and management process of any urban river rehabilitation effort. • Within general Project Appraisal a variety of different modules are proposed. Most common seems the sequence (cf. Schmickler 1986, Marti and Stutz 1993, Heitzer 2000): – Implementation Control (as planned / as built control) – Effectiveness Control (effects the implementation caused in general and single measure related) – Control of Goal Achievement (Performance control) – Effect Analysis (why did certain effects occur / not occur). • An important element emphasised by all authors is the feedback of success appraisal to the project management to allow for adjustments in the scope of adaptive management. • Because of the close relationship to issues of urban development (cf. Schanze et al. i. p. ) urban river rehabilitation must be seen also in their urban context and in relation to urban planning.
Appraisal Phases: Phase 1. Pre-project appraisal data collection Output: -Objective setting -Set scope of monitoring programme -Define success criteria : Appraisal Steps: Desk study Site selection Problem definition Statement of project goals Securing resources Pre project baseline data collection Phase 2 Project design and implementation Output: Adaptive Management Project design Construction Phase 3 Post-project appraisal and Post- project data collection Adaptive Management Post- project appraisal Output: -Document project success/failure Project Failure -Publicise results of Long term management project appraisal programme -Increase knowledge base -Process of refinement and development Figure 2: Post Project Appraisal and adaptive management (Bruce-Burgess and Skinner 2002)
• Marti and Stutz (1993) propose the differentiation of compliance audit and performance audit (Downs and Gregory 2004, p. 230) Current state Historical development Leitbild Target definition Coordination Target analysis Prognostic assessment of success (Evaluation of measures) Implementation plan Monitoring concept Implementation Monitoring Implementation control Assessment of target achievement Assessment of effectiveness Figure 3: Steps of Project Assessment (translated from Marti and Stutz 1993, p. 125)
Post project monitoring and review as part of project management Phase of planning and implementation • Problem Definition Project Definition Baseline Surveys Feasibility Definition Design Construction Post- investment operation Figure 4: Post project monitoring and review (modified and considerably shortened from Gardiner 1991 a, p. 9) Revise Plan Define Restoration Measures Determine Need for Project, General Objectives Secure Resources Study Historic Channel Conditions Define Evaluation Criteria Define Evaluation Techniques Propose Contingency Measures • Review by Agencies and Public Implement restoration Measures Evaluate success Determine if Budget is Adequate Figure 5: Success evaluation in the process of project realisation (Kondolf and Micheli 1995, p. 3)
1. 4 Defining the scope for success appraisal 1. 4. 1 Target dimension • • • The availability of clearly defined and generally accepted goals is the most important prerequisite for an appraisal of success. Without precisely defined goals, the core element of post implementation assessment – the establishment of goal compliance – will not be possible. it is indispensable that targets be defined already in the process of project planning Targets need to be operationalised. Each target must be furnished with at least one fully practicable indicator Generally, targets can be: a) strategic targets; b) management targets and c) targets for single measures (Marti and Stutz 1993).
1. 4. 2 Effect dimension • • It is supposed, that rehabilitation activities cause certain effects. Generally these can be classified into intended and unintended effects. Generally, two different perspectives on cause – effect relationship are important The cause-effect relationship Cause Effect (e. g. targeted change) Cause (e. g. single measure, environmental conditions etc. ) Effects (e. g. targeted change) Figure 6: The cause-effect relationship (Hellstern and Wollmann 1984, p. 36) • In practice, a three step approach is useful to evaluate with intended and unintended effects: 1. Effect analysis 2. Effectiveness analysis 3. Efficiency analysis)
1. 4. 3 Scale of Assessment Abstraction dimension • Evaluation of urban river rehabilitation generally can refer to different organisational levels: · Program level. · Project level. · Measure or Effect level. 1. 4. 4 Space dimension of effects the following spatial dimensions of effects are distinguished: Water level: considering effects that occur directly in the water body (e. g. water quality improvements). Stream reach level: considering effects in certain stream sections in the project area. Impact area level (hinterland): considering the urban area, where no intervention has taken place, but which is influenced by the changed conditions in the rehabilitation site (social catchment).
1. 4. 5 Time dimension • • The time, necessary to complete post implementation assessment can vary from months to years and even decades, depending on the speed of the stream system’s response to the treatment applied (FISRWG 1998, p. 6 -39 sq. ). Kondolf (1995) suggests that the “commitment to the long term” is necessary for the appraisal of ecological success to capture delayed effects that materialise only after years.
1. 4. 6 Interpretation of results • Five levels are distinguished for the development of a parameter: – Baseline, representing the current state of target issues and framework conditions. – Prognosis, being the expected development without intervention, determined ex-ante by assuming a certain development of relevant framework conditions. – Trend, being the real development that would have occurred without intervention, determined ex-post by comparing the assumed development of related framework conditions and their real development. – Real development observed after the intervention. – Target, being the defined goal for the development of the parameter of interest.
Defined goals/ targets (ex ante) Target ∆2 Observed development (ex post) Real Development ∆4 Effectiveness ∆1 Observed trend of external conditions (ex post) Expected development without intervention (ex ante) Trend Degree ∆3 of Success Prognosis ∆6 ∆5 ∆7 Baseline Current state of target issues and framework conditions (ex ante) ∆ 1: Target-Baseline comparison Figure 7: Levels of information for success appraisal (translated from Hellstern and Wollmann 1984, p. 39) ∆ 2: Target-Real development comparison (planned development) ∆ 3: Baseline-Real development comparison (degree of goal achievement) ∆ 4: Real development-Trend comparison (actual target effectiveness) ∆ 5: Baseline-Trend comparison (effects of external factors) ∆ 6: Trend-Prognosis comparison (prognosis failure margin) ∆ 7: Prognosis-Baseline comparison (expected development without intervention)
1. 4. 7 Conclusions / prerequisites for the assessment 1. The setting of rehabilitation targets (objectives, goals, etc. ) 2. Definition of performance indicators 3. Availability of benchmarks 4. Establishment of baseline conditions 5. Appropriate monitoring frequency 6. Spatial adequacy of data time aspect 7. Consideration of the trend without intervention 8. Damping of effects
1. 5 Development of indicators for post implementation assessment 1. 5. 1 Existing indicators and indicator systems for appraisal of urban river rehabilitation • • • it can be summarised, that currently there is practically no systematic post implementation assessment in urban river rehabilitation projects. Only singular attempts can be realised, but which in general are not consequently in the overall project management The used monitoring parameters and indicators are as follows: Ecological monitoring Hydrology and hydromorphology – Hydrological regime (incl. NQ, MQ, HQ) – Bank full flow conditions – Sediment balance – Bed shear force – Stream morphology – Cross section
• Water quality – – • Flora – – • Invasives Shrubs Trees perennials Fauna – – – – • Chemical Biological Physico-chemical (e. g. automated dissolved oxygen) Different groups of pollutants Aviofauna Ichtiofauna Invertebrates Mammals Amphibians Sediment concentrations Nutrient concentrations Other – Soil pollution (heavy metals) – Potential for re-colonisation of river section – Land use distribution (e. g. percentage of impervious area within the basin)
Social and economic aspects • • • River rehabilitation in urban areas may have significant impacts on social and economic well being. Social and economic aspects have rarely been explicitly considered for appraisal in the context of urban river rehabilitation. An extensive public perception study was carried out for Skerne River and Kaitzbach. Following aspects have been considered: – Social • Public perception of rivers, • Public acceptance and awareness • Stewardship and advocacy • Stakeholder network • Ownership • Built structure • Aesthetics • Recreational value
• Economic – Economic appraisal – Cost measurement • Methods, applied for the assessment of social, aesthetic and economic aspects were: – Stakeholder analysis – User surveys – River Landscape Assessment – Photo documentation and – Cost-benefit- analysis • Other aspects – A number of further aspects where considered in site appraisals: • Historical conditions • Flood potential • Watershed problems
1. 5. 2 Criteria for the choice of indicators • • • A central element for the choice of indicators for an indicator system is the orientation along the defined ‘Leitbild’ (cf. Kern 1994, Kondolf 1998, Birkmann et al. 1999). Scientific requirements for criteria – Theoretical soundness – Measurability – Predictability – Scientific credibility – Temporal Sensitivity – Spatial Resolution – Robustness Organisational requirements for criteria – User and policy relevant – Comprehensibility and communicability – Efficiency and practicability – Participation – Obligation
2 Method for post implementation appraisal 2. 1 Existing Methods of Indicator Based Project Assessment – The following is a presentation of existing multi-criteria assessment methods, that were found to be especially applicable to assist the development of a PIA method for urban river rehabilitation. Polyfunctional Assessment Method (Pf. AM, Grabaum 1996) – The Pf. AM is an ex-ante multi-criteria assessment method, to determine the best land use option for a site. 1. Formulation of objective functions 2. Determination of parameters for objective function 3. Weighting of parameters for each objective function 4. Assignment of impact function to each parameter related to the objective function 5. Assessment of best land use option trough the combination of parameter weight and impact function
FLAG Method (Nijkamp & Ouwersloot 1998) • The FLAG Method comprises a multi criteria decision method, similar to the Pf. AM Method It is used to analyse regional sustainability based on “a [operationalized] set of minimum (or critical) conditions to be fulfilled” (Nijkamp & Ouwersloot 1998, p. 4). • It considers ecological, economic or social objectives and identifies three steps for the assessment of sustainability: 1. Identification of a set of measurable indicators 2. Establishing normative reference values 3. Development of a practical impact methodology for assessing (future) developments Section A: green flag: no reason for specific concern Section B: orange flag: be very alert Section C: red flag: reverse trends Section D: black flag: stop further growth Figure 8: A range of Critical Treshold values for fuzzy CTV’s (adopted from Nijkamp & Ouwersloot 1998, p. 10)
2. 2 Procedure for the establishment of a project specific indicator system for urban river rehabilitation • The decision to use an indicator system needs to be taken early on and the set up of such a system is closely correlated to the definition of goals, objectives and targets for a urban river rehabilitation project. The following method will include the following: 1. 2. 3. 4. 5. 6. 7. Setting goals and objectives Selection of a project specific set of indicators Defining target values and value classes for indicators Weighting of indicators Assessment of parameters Aggregation of data Presentation of results
2. 2. 1 Setting General Goals and specific Objectives • General goals of rehabilitation projects should comply with sustainability requirements and should therefore cover ecological, social and economic aspects. ECOLOGIC ASPECTS SOCIAL ASPECTS Increase Biodiversity Improve Hydrological conditions Improve Morphology and continuity Improve Water quality Establish participative processes Enhance and provide recreational values Provision for public safety and health ECONOMIC ASPECTS Low costs of maintenance Use of Cost effective measures Stimulation of investment Table 2: Potential General Goals related to urban river rehabilitation
2. 3 Establishing a Monitoring plan • • Monitoring before, during and after a urban river rehabilitation project provides the basis for a continuous project assessment. Following aspects should be incorporated (adapted from Glasson, et. al. 1999; FISRWG, 1998; SFW, DEPMWCG, 2001): – Monitoring Statement: Overview of project background, short version of mission statement, goals and objectives, participants and procedures – List of Indicators: Set of measurable indicators and their description as well as potential sub-sets of indicators – Monitoring Matrix: when, where and how to measure (assessment methods), potential alternatives, Statement of adequate duration for post implementation assessment – List of Responsibilities: for assessment, evaluation and reporting – Report Statement: Form and Frequency of public reporting – Cost Statement: Funding needs and potential sources
2. 4 Application considerations • • • The URBEM method for appraisal of success described above (see chapter 3. 3) is meant to be adapted, to different projects types, project size, available budget and needs for decision making. For complex, large scale projects additional methods (cf. annex 3) may be incorporated into the appraisal procedure and different supporting tools may be used. Geographic information systems (GIS) provide one powerful tool to manage multi-layered information. 2. 5 Framework for irregular Post Implementation Assessment • • The concept of post implementation assessment for urban river rehabilitation projects, that has been outlined above requires a precise procedure, which doubtlessly is not yet widely practised. The following particular problems may occur: – Imprecise definition of targets, missing indicators – zero-option for prognosis/trend is missing – Missing baseline data – Assessment procedures for indicators cannot be reproduced
3 Description of Criteria and Indicators 3. 1 Hierarchy of Criteria and Indicators • The structure of the URBEM indicator set consists of several thematically differentiated levels and is laid out to fulfil two major functions. Level I Overall project success level expressing the overall success of the rehabilitation project Level II (Category) Success level, described by three main categories: Ecology, Social and Economy Level III (Sub- Category) Success level, thematically differentiating the categories Level IV (Component) Success level described by groups of rehabilitation elements Level V (Quality element) Success level, described by single rehabilitation elements Table 3: Structure of the proposed indicator system
3. 2 Criteria and Indicators of Ecology • • Contemporary water management, which also includes river rehabilitation in urban areas in Europe is heavily influenced by the European Water Framework Directive (cf. EC 2000, Schanze et al. i. p. ). The overall aim of the WFD for surface waters is to achieve “ good ecological status” and “good surface water chemical status” in all bodies of surface water by 2015. Therefore, ecological indicators of success are based on the systematic introduced by the WFD. In the following, the structure of ecological indicators of success is presented.
CATEGORIE SUB-CATEGORIE COMPONENT (*WFD) Biological elements* Biodiversity QUALITY ELEMENTS (*inland surface waters- river as defined by the WFD) Composition and abundance of aquatic flora* Composition and abundance of benthic invertebrate fauna* Composition, abundance and age structure of fish fauna* Hydrological regime* Hydrology Quantity and dynamics of water flow* Connection to groundwater bodies* River Ecology Morphological conditions* Morphology River depth and width variation* Structure and substrate of the river bed* Structure of the riparian zone* Lateral connectivity Continuity* Water Quality General chemical & physico chemical elements* Specific pollutants* Other Individual Figure 12: Structure of the indicator system – ECOLOGY River/Stream Continuity* Thermal conditions* Oxygenation conditions* Salinity* Acidification status* Nutrient conditions* Pollution by priority substances* Pollution by other substances* Individual, not water related elements
3. 3 Criteria and Indicators of Social Well-being • For the purpose of post implementation appraisal a hierarchy of social as well as economic criteria is proposed, which is open to be adapted to the local conditions in which a rehabilitation scheme takes place.
Figure 13: Structure of Social Criteria for Urban River Rehabilitation
Public Accessibility to River and River Site • • • In past times public access to rivers has often been limited, due to industrial uses or concentration of infrastructure lines Private property rights often limit access to rivers, making access an act of illegal trespass. Urban river sites have a great potential to satisfy different recreational needs Public access is of paramount importance in any urban river rehabilitation project and should be analysed. The sub-category of accessibility may include the following quality elements: – Access from city to site – Physical access to the water – Access from river to site – River crossings
Open Space Extend and Quality • • • Open space includes public as well as private and semi-public areas. Open space is an important resource for outdoor recreation (Lynch, 1998) and a place, where stress can be relieved particularly in densely populated urban areas. The following quality elements are suggested – Extend of open space – Spatial qualities of open space – Sensorial qualities of open space Quality and Extend of Recreational and Cultural Facilities • • The before mentioned study showed that active and passive recreation as well as educational aspects played an important role in many rehabilitation projects. The potential of sites to fulfil such functions can be measured through the quality and quantity of cultural and recreational facilities including: – Quality and amount of recreational facilities – Cultural events – Quality and Amount of natural and cultural heritage sites – Provisions for environmental education and awareness
Incidents and Provisions related to Public Health and Safety • • • Over the past decades European cities have been experiencing an ever increasing frequency of flooding with affiliated losses. Flood damage to structures and flood related threats to public health and safety are a limiting factor in urban stream restoration. Riverfront sites often consist of derelict land abandoned land in rundown neighbourhoods. In relation to the evaluation of health and safety the perception of risk may be accessed, which may differ from the expert assessment and provide additional information to decision makers. Quality elements include: – Provisions for public health and safety – Accidents and health related incidents – Type and quantity of crime
Quality and Density of Land Uses • • Type, quality, and density of land uses that abut a urban river improvement site are bound to change. The following quality elements will be considered – Quality and density of housing – Quality and density of commercial, industrial and utility uses 3. 3. 2 Public Appreciation and Utilization of River and River Sites • • A survey of public appreciation reflects how much a river and a river site is appreciated and how it is perceived, by measuring values people attach to a place. In many cases river rehabilitation initiates neighbourhood revitalisation, changing the social structure of the residents and their quality of life.
Public Appreciation of River and River Sites • • The values of people, their perception and attitudes toward the pre- and post project environment, should be included in any audit (cf. Stolp, 2003) of residents or user groups. Quality elements to be assessed include: – Perception of public health and safety – Sensory perception – Perception of place identity – Perception of restorative capacity Recreational Use and User groups • • • Existing conditions of a site influence its suitability for uses by different population groups. Which recreational needs a site can fulfil and how well it is accepted by visitors or residents determines by whom, how, and how much it is being used. Quality elements include: – Recreational user groups – Amount and diversity of recreational activities
Residential Use and Social Structure of Residents • • • River sites are highly desirable for residential uses (Wagner et. al, 2003), due to their amenities. Urban river rehabilitation, depending on its size and accompanying neighbourhood revitalisation, may have a significant impact on existing and future residents. This subcategory particularly applies to rehabilitation schemes, that bring about significant change in urban quality and residential use: – Social structure of community – Quality of residential Use
3. 3. 3 Social Relations and Social Organisation • • Projects of participative nature often have a significant impact on social relations of stakeholders and may result in greater community cohesion and in a greater trust in institutions. Those relations are described by the term “Social capital” Social capital makes cooperative action possible and describes the capacity of the community to act together to improve their quality of life In context of river rehabilitation, social capital helps a community to more effectively pursue enhancement objectives based on shared values and interests.
Neighbourhood Relations and Neighbourhood Cohesion • • Residents living in a certain area tend to establish relations with the people living around them and sharing their interests. Following quality elements may be considered – Quality and size of neighbourhood networks – Trust in neighbourhood Relations between Institutions/Organisations and Residents/Stakeholders • • Quality and organisation of relations between institutions and organisations on one side and stakeholders on the other side will influence a projects outcome. High trust in institutions to act and decide in accordance with the community values, participative planning and decision making will increase social sustainability of any environmental project. Levels of active involvement may vary from plain information to active involvement, arbitration and codetermination. Following quality elements may be assessed: – Stakeholder participation – Public trust in institutions and organisations
3. 4 Criteria and Indicators of Economic Sustainability • • Rehabilitation of urban rivers will attract visitors and residents, but can also attract new business to the site and upgrade economically depressed sites. River rehabilitation can result in a range of economic benefits, including (Otto et. al, 2004): – Reduce costs of drinking water treatment due to improved water quality – Curb flood damage and lower cost of flood control – Decrease storm water management cost – Revitalise riverfronts with new opportunities for housing, offices and commercial services that attract new residents, business and visitors – Provide new jobs for residents in construction and commercial business – Offer recreational opportunities, open space and park amenities – Raise property values and generate new tax revenues – Attract state and federal founding, new volunteers and broad financial support
Category Production values Subcategory Water Resources and Energy Supply Subca te-gory Drainage and Waste Disposal Transport of drainage water and wastewater (point source and non-point source pollutants) Table 4: Utility values Use Values Such as recreational use, economic activities, shipping, employment, property values and tax revenue values. Non-use values such as values attached to endangered species, or an aesthetically pleasing view
Figure 14: Structure of Economic Criteria for Urban River Rehabilitation
3. 4. 1 Production Values • • The WFD paced special emphasis on economic aspects of urban river uses through the paragraphs concerning “Heavily Modified Waterbodies”, recognizing the values of rivers for shipping, water power, water supply, storm water drainage and waste disposal. Subcategories to assess under production values include – Water Resources and Energy Supply – Drainage and Waste Disposal 3. 4. 2 Utility Values • • The value of a river and its setting can be divided into use values and nonuse values. Use values relate to use of land- and water areas for housing, recreation, commerce and utilities, while non-use values include such as a view of a site or its natural condition seems to offer no immediate monetary value, though a value it has.
Direct Use Values • • Land water areas along rivers offer opportunities for economic gain. They do however suffer the “tragedy of the commons”, having been a free for all in waste disposal. Water quality improvement of rivers came at a cost, born by the public in improving sewage treatment. – Property values and taxes – Recreation and amenity values – Economic activities and employment Non-Use Values • • Nature preserves set up to protect species abundance and diversity without offering public access provide no direct economic gain, though they offer long range benefits to humanity. No-use values may be accessed for their economic value, but quantification requires elaborate methods and expert knowledge.
3. 4. 3 Project Costs and Maintenance costs • The category project cost and maintenance cost has been included to enable the assessment of a cost benefit ratio. Project costs • The following quality elements should be considered for the assessment of project cost: – Planning costs – Construction costs – Real estate Purchase Maintenance costs • • • A successful cost-effective river rehabilitation project will consider also “operating costs” after the project has been implemented. As a self sustaining equilibrium of the river should be achieved, a successful river rehabilitation will keep annual maintenance costs as low as possible. Maintenance cost can be divided in annual maintenance costs, which may include such costs as for mowing and for weed control and event related maintenance related to flooding.
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