Improved water retention capacity in the agricultural landscape

Landscape features and structural changes in the land use of an area require cooperation and trust among farmers and other stakeholders in the area such as surrounding inhabitants, local industries or landowners. If the creation of larger structural projects such as reservoirs or flood paths is needed, this will require government or landowner permissions. Water storage options could also benefit for local businesses or inhabitants and involve a regional or municipal investment/collaboration. 

In most cases, this type of measure is considered promising because the design is often multi-functional and thus combines different interests (see the section on Costs and Benefits). Implementation of landscape features is often implemented in combination with buffer zones or habitat corridors which contribute to local biodiversity, landscape connectivity and soil moisture retention capacity. Integrated spatial planning of the whole territory that incorporates farmland water storage structures into the landscape can favour the initiative’s success. 

Implementing this option requires careful site-specific assessments to achieve the expected benefits. Soil and slope characteristics, crop types, and local weather conditions must be considered before implementing water runoff designs and location decisions for water storage or ponds.  Micro design of measures, which considers local conditions, like where to establish new features in the landscape, is necessary because the risk of adverse effects exists if not designed accurately Risks include flooding or unintended water flows which end up in agricultural areas or inhabited areas. Care needs to be taken in the design of landscape features to ensure that the location of groundwater storage is also safe from these effects if overflow occurs or leakage or freeze. In addition, if the option is not correctly implemented (without proper planning and considering all ecosystem components), risks of damage to agricultural crops are possible, especially in flat or flood prone areas, due to the creation of higher groundwater tables. Under certain conditions (ex. close to the sea or ocean), some of the proposed water retention options may affect salinity, changing the soil quality very drastically or making the earth unsuitable for some crops unless irrigation plans are appropriately adapted to the new hydro-geological forms. Terracing reduces run-off and increases water infiltration, but changes in the hydrological regime may have a significant visual impact in contrast with the surrounding natural vegetation and traditional plantations. 

On the broader level, adequate landowners’ compensation is necessary, and projects must address not only design and implementation but also the behavioural change of land users. This option may require substantial investments depending on the water retention option applied. An issue in planning and implementation is the complexity of governance and coordination as private and public parties usually may be involved. Gathering support from the many stakeholders involved and planning for the investment may be a limiting factor.  

Beyond climate change adaptation against floods and droughts, other benefits are associated with implementing this. 

The benefits of this adaptation include better water retention or storage for times of drought; and flood disaster risk mitigation, provision of blue-green ecosystem services, reduced need for irrigation, and improvement of soil quality. The latter in turn, supports soil biodiversity, increases the presence of natural enemies, helps nutrient storage, and generally supports crop growth.  

This measure contributes to several EU policies (Natura 2000, Common Agricultural Policy see the section on legal aspects below). These options may also reduce agriculture production fluctuations, bringing farmers security and makes food production more reliable. Agricultural production can increase, often in neighbouring regions.  

This option is generally considered very effective even if some measures have high entrance costs. In fact, costs are highly variable, depending on the scale of the intervention and the selected measures. Efforts and costs for maintenance should also be considered for the long-term effective planning of the measures. 

An example of a cost-benefit assessment of water retention improvement integrated into the landscape can be found in the case study Tamera water retention landscape to restore the water cycle and reduce vulnerability to droughts. 

The EU Common Agricultural Policy can foster this option, which supports initiatives that tackle climate change and the sustainable management of natural resources, as well as maintain rural areas and landscapes across the EU.  

Under the Green infrastructure EU Strategy, there is more attention to measures that aim to enhance the functioning of natural processes and ecosystems so that water can better infiltrate and be stored. Natural Water Retention Measures (NWRM) can be used to contribute to the objectives of the EU Water Framework Directive (WFD) and/or the EU Floods Directive. Funding might also be sought from the European Regional Development Fund, the European Social Fund and the Cohesion Fund.  

Management measures must fit into the specific local context and must be compliant with national and subnational regulations and plans (e.g. spatial planning, Natura 2000 sites, river basin management plans, flood risk management plans).

Depending on the type of landscape features being implemented, the time frame could be short (in the case of contouring practices, possibly in one season); however, with larger projects involving water storage, drainage systems, flow regimes, or reservoirs, more stakeholders involved, and research needing to be conducted in the planning stages this could take several years to implement- depending on the costs and number of stakeholders involved. 

Lifetime can be 20 years or more, depending on management complexity, capacity and maintenance.