Implementation of water retention ponds in agricultural land: the Lamone river case

Climate change is affecting water quantity and quality, posing challenges particularly for what regards agricultural production. The use of nature-based solutions to address these challenges is increasing. Natural water retention ponds have been identified as viable solutions for water management in agriculture. This paper aims to characterize water retention ponds, to quantify their effectiveness, their direct and indirect benefits, and costs. The paper analyses the case of the Lamone river catchment in Emilia Romagna Region (Italy), where water flow and availability show large seasonal variability. This is an area of important agricultural production (particularly for kiwi plantations) heavily relying on irrigation. Here water retention ponds are systematically applied to store water in winter that can be used during the dry summer season. They can play a strategic role in ensuring irrigation water availability while preserving the minimum environmental flow. The paper analyses both the benefits of ponds for the water balance at sub-catchment scale, and the environmental effects produced by ponds having an ecological functionality. We refer to a scenario of implementation of new ponds, and we appraise the contribution of new ponds whose siting is chosen in order to maximize landscape connectivity. The hydrological effects of the new ponds are evaluated under present and climate change scenarios. We show how water retention ponds may increase water availability for irrigation, while improving the river flow regime. More water for irrigation can be associated to additional agricultural production, while a more ecologically oriented design of ponds may lead to landscape ecological improvements. The investment costs of ponds are justified in economic terms, and the additional costs of improved design are expected to be balanced by the ecosystem services obtained. The business model required to operate this type of intervention is discussed, together with potential funding channels. In particular, we discuss two innovative incentive models based on compensation of land and production lost and on tradable development rights.

Application ID		Italy_01
Application Name		LWR in a mountainous environment
Application Location		Country	Italy	Country 2 (in case of transboundary applications)
		NUTS2 code		2
		River Basin District Code		Po district
		WFD Water Body Code
		Description		Nature-based water retention ponds in upper Lamone River catchment in Emilia Romagna Region
Application Site Coordinates (in ETRS89 or WGS84 coordinate system)		Latitude (WGS84): 44.197909		Longitude (WGS84): 11.761707
Target Sector(s)		Primary:		Agriculture
		Secondary:		Nature
Implemented NWRM(s)		Measure #1:		N1 Basins and Ponds
		Measure #2:
		Measure #3:
		Measure #4:
Application short description		Developing new ponds and converting exiting grey ones to green to sustain agriculture and provide environmental benefits

Brief description of the problem to be tackled		This case study aims to characterize water retention ponds, to quantify their effectiveness, their direct and indirect benefits, and costs.
What were the primary & secondary targets when designing this application?		Primary target #1:		Regulation of hydrological cycle and water flow
		Primary target #2:
		Secondary target #1:		Biodiversity and gene-pool conservation in riparian areas
		Secondary target #2:
		Remarks:		Benefits also outside riparian areas due to increase ecological connectivity
Which specific types of pressures did you aim at mitigating?		Pressure #1:	WFD identified pressure	Water balance
		Pressure #2:
		Pressure #3:
		Pressure #4:
		Remarks:
Which specific types of adverse impacts did you aim at mitigating?		Impact #1:	WFD identified impact	Stress during dry season
		Impact #2:
		Impact #3:
		Impact #4:
		Remarks:
Which EU requirements and EU Directives were aimed at being addressed?		Requirement #1:	WFD-mitigation of significant pressure
		Requirement #2:	WFD-achievement of good ecological status
		Requirement #3:
		Requirement #4:
		Remarks:
Which national and/or regional policy challenges and/or requirements aimed to be addressed?

Dominant Land Use type(s)		Dominant land use		3.1.1: Broad-leaved forest
		Secondary land use		2.2.2: Fruit trees and berry plantations
		Other important land use
		Remarks: irrigated fruits
Climate zone		cool temperate moist
Soil type
Average Slope		sloping (5-10%)
Mean Annual Rainfall		900 - 1200 mm
Mean Annual Runoff		300 - 450 mm
Average Runoff coefficient (or % imperviousness on site)		0.3 - 0.5		40 - 60%
		Remarks: -
Characterization of water quality status (prior to the implementation of the NWRMs)
Comment on any specific site characteristic that influences the effectiveness of the applied NWRM(s) in a positive or negative way		Positive way: water availability in winter
		Negative way: land availability

Project scale		Small (e.g. farm, plot, building complex, block)
Time frame		Date of installation/construction (MM.YYYY)
		Expected average lifespan (life expectancy) of the application in years
Responsible authority and other stakeholders involved		Name of responsible authority/ stakeholder		Role, responsibilities
		Land reclamation Authority		Technician
		Farmers		Owners
The application was initiated and financed by		European Commission - Joint Research Center
What were specific principles that were followed in the design of this application?		water sensitivity, functionality, environmental benefits, costs
Area (ha)		Number of hectares treated by the NWRM(s)		Number of ha: 1000 ha of fruits (kiwi) can be sustained by new ponds without compromising the water balance of the river
		Text to specify		area covered by new ponds≈500 ha
Design capacity		Water storage capacity in the year round 5.3 Mm3
Reference to existing engineering standards, guidelines and manuals that have been used during the design phase		Reference		URL
		1	Regional price lists for soil defense works	https://territorio.regione.emilia-romagna.it/osservatorio/Elenco-regionale-prezzi
		2
		3
		4
		5
Main factors and/or constraints that influenced the selection and design of the NWRM(s) in this application?		Ecological connectivity improvement, slope, distance from the river, land use, legal obligations for permitting

Impact category		Impact description		Impact quantification
				Parameter value; units and/or	% change in parameter value as compared to the state prior to the implementation of the NWRM(s)
Runoff attenuation / control
Peak flow rate reduction
Impact on groundwater
Impact on soil moisture and soil storage capacity
Restoring hydraulic connection
Water quality Improvements
WFD Ecological Status and objectives
Reducing flood risks (Floods Directive)
Mitigation of other biophysical impacts in relation to other EU Directives (e.g. Habitats, UWWT, etc.)
Soil Quality Improvements
Other		Water availability in summer		From 3.96 Mm3 to 4.95 Mm3 for downstream sub-catchment	+25%

What are the benefits and co-benefits of NWRMs in this application?		Direct benefits: Increased water availability in agricultural land for irrigation Increased biodiversity and habitat quality (vegetation and fauna) around and within ponds Indirect benefits: Support ancillary social and economic activities (wood production and social/educational farms)
Financial costs Value in € (Total + possible breakdown)		Total extra-costs for green ponds construction:	140.000,00 €	Total cost including construction and yield loss for a green water retention pond of 50000 m3> of water volume over 20 years
		Construction costs (grey ponds)	12,00 €/m3	Costs include excavation, waterproofing of the bottom and perimeter fence
		Construction costs (green ponds)	14,00 €/m3	Costs include excavation, waterproofing of the bottom and perimeter fence, cost of additional land, floating island
Were financial compensations required? What amount?		Was financial compensation required: Yes (proposed)
		Total amount of money paid (in €): -
		Compensation schema: Land swap Tradable Development rights
		Comments / Remarks: compensation scheme proposed to compensate the extra-cost of building ponds in a greener approach
Economic costs		Cost of kiwi production loss due to greener ponds (50000 m3): 0,03-0,05 €/m3/year
		Additional costs: -
		Other opportunity costs: -
		Comments / Remarks: -
Which link can be made to the ecosystem services approach?		Water provision for agriculture Water security (water availability in rivers) Food security (agricultural production support) Amenities (increased biodiversity, habitats, landscape quality)

Monitoring requirements		Water balance revision, 5 – 10 years
Maintenance requirements		Very limited, vegetation cleaning nearby ponds
What are the administrative costs?		Very limited

Which assessment methods and practices are used for assessing the biophysical impacts?		Landscape connectivity indexes
Which methods are used to assess costs, benefits and cost-effectiveness of measures?		Regional price lists for main cost voices applied to schematic ponds of different size
How cost-effective are NWRM's compared to "traditional / structural" measures?		Extra costs are limited to circa 10% of grey solutions
How do (if applicable) specific basin characteristics influence the effectiveness of measures?		Topography, river distance, position compared to relevant areas for the ecological network (as forests) influence the effectiveness
What is the standard time delay for measuring the effects of the measures?		Years to check effect on the water balance on average

What were the main implementation barriers?		Land availability and additional costs to be covered, legislative restrictions
What were the main enabling and success factors?		Water need is high, and ponds can cope with it
Financing		Tow innovative incentive schemes have been elaborated, compensating farmers with land or in monetary terms
Flexibility & Adaptability		Nature-based ponds are simple solutions to adapt to broad spectrum of contexts
Transferability		Fully transferrable, data to design and study effectiveness are available pan EU

Key lessons

(nature-based) ponds showed their beneficial role in agricultural landscape, (water availability and habitat quality) in present and future climate change scenarios. Farmers and experts confirmed the complementary environmental benefits related to water retention ponds, which act as stepping-stone across the landscape supporting biodiversity and habitat quality for wildlife. Additional costs to farmers (construction and agricultural production loss) shall nonetheless be compensated by new incentive schemes

Source Type		Journal
Source Author(s)		Cassani Gabriele
Source Title		The Water balance: A methodology for evaluating the compatibility between surface water resources and environmental and anthropic requirements
Year of publication		2009
Editor/Publisher		L’Acqua, n.2, pag.45
Source Weblink		https://www.idrotecnicaitaliana.it/sommari/il-bilancio-idrico-una-metodologia-per-la-valutazione-della-compatibilita-tra-risorsa-idrica-e-idroesigenze-ambientali-e-antropiche/
Key People		Name / affiliation		Contact details
		Franchini Marco
		Galeati Giorgio
		Mazzoli Paolo

Source Type		Journal
Source Author(s)		Maes Joachim
Source Title		More green infrastructure is required to maintain ecosystem services under current trends in land-use change in Europe
Year of publication		2015
Editor/Publisher		Landscape Ecology, 30, 517-432
Source Weblink		https://link.springer.com/article/10.1007/s10980-014-0083-2
Key People		Name / affiliation		Contact details
		Barbosa Ana
		Claudia Baranzelli
		Grazia Zulian
		Felipe Batista e Silva et.al

Source Type		Journal
Source Author(s)		Renard Vincent
Source Title		Property rights and the 'transfer of development rights: questions of efficiency and equity
Year of publication		2007
Editor/Publisher		The Town Planning Review, 78(1), 41-60
Source Weblink		https://www.jstor.org/stable/40112701?seq=1#metadata_info_tab_contents
Key People		Name / affiliation		Contact details