An inland shore is an area for water storage connected to a nearby lake or river in which ecosystem services are optimized for multiple land use, thereby creating new economic opportunities. Large water level fluctuations are taken into account in advance and optimizing sustainability is the main theme in the whole concept. are connected to the lake or river through inlets in the dike. Connections to the regional water system are optional but advisable. can store and release water if needed, allowing the area to function as a climate buffer and freshwater storage. In addition, the design takes into account the possibility to function as a helophyte filter to allow improvement of water quality which is considered to be essential for proper functioning. Additional functions (e.g. recreation, fishing, aquaculture, floating infrastructure for living and working, sustainable energy production by sun, wind and water, floating agriculture, nature development) can be added depending on the desires of stakeholders.
The concept is based on the idea that climate change will increasingly lead to extreme weather that can damage existing land use functions through floods and droughts, and on the idea that freshwater is a valuable resource that provides economic opportunities if properly managed.
The Netherlands has more than enough water due to a net rainfall surplus and inflow of river water from Rhine and Meuse. Still, water shortages are occurring as most of this water is directed towards the North sea and becomes unavailable when needed. A solution to this problem is to store water in large water bodies. Lake IJsselmeer is such a body but on the long term water level fluctuations are limited due to the presence of existing infrastructure. Another possibility is to seek extra storage capacity for water on land by construction of inland shores. This expands the storage capacity of the lake, but also brings additional benefits for the functioning of the lake and new prospects for economic development. For instance, at present the fish stock of lake IJsselmeer is low due to over-exploitation by the fishing industry. With the current design of the coastline of lake IJsselmeer possibilities for spawning and fish reproduction are limited due to a lack of suitable habitats. can provide these suitable habitats with great potential for enhanced ecosystem services and recovery of commercial fishing.
Inland shores can also contribute to increased safety from flooding. Currently excessive pumping and drainage causes land subsidence in the Netherlands. In addition, accelerating sea level rise will increase water levels around us. One option is to raise and reinforce dikes but the question is to what level? Flood risk is expressed as the product of chance and consequences, and we are professionals in building dikes, but what if the dike still fails? Due to the high economic value of land and infrastructure behind the dikes the consequences will be very dire. In addition, huge dikes will detach the Dutch inhabitant from the water which harbours beautiful scenery and nature values and which has always been part of our history. Besides, with high and secure dikes we may still be confronted with flooding due to extreme rainfall events. can be used to store the excess of water coming from the sky or from large water bodies. The concept is a fundamental breakthrough in current water management practices of ongoing pumping, drainage and land subsidence which in the end will not be sustainable.
Besides benefits for future robust water management and benefits for commercial fishing many other benefits are to be explored. For example, inland shores can become attractive areas where people can live and work. The Netherlands is experimenting with houses on water. Inhabitants of inland shores have lots of possibilities for nearby recreation on or near the water in beautiful scenery. Agriculture may benefit because in an inland shore there is a secure freshwater source despite more extreme floods and droughts. Floating glasshouses are possible, which can also be used to generate energy in a sustainable way using sun radiation. In addition, differences in water level can be used to generate sustainable energy.
Inland shores can support climate services if carbon is captured from the atmosphere and stored under water. Depending on the management regime, wetlands can be efficient ecosystems for carbon capture. Also these systems can be used for nutrient retention enhancing the water quality. Improvement of the water quality is important for the Netherlands which in many locations has enriched nutrient levels in water and sediments. In a warmer climate this constitutes a risk in relation to algae bloom. can also contribute to nature conservation objectives linked to the WFD, Natura 2000 and national objectives for nature.
In all, these developments will open opportunities for regional and national economic development. However, bringing inland shores from theory to practice will need a transition in Dutch thinking on water management. Can we develop sufficient economic value by living with and on top of water? This will desire a whole suite of innovative concepts in living, working and transport.
There is no exact blueprint for an inland shore. It is a concept and active stakeholder involvement is needed on the regional level to fill in the details based on ideas of stakeholders about economic opportunities and desires. Eventually, a ring of high quality wetland areas can be created around lakes where ecosystem services are optimized for different land use functions, that provide more space for water in a world with a changing climate, and bring new opportunities for economy and quality of life in deltas like the Netherlands.
Comparable applications in marine environments are described in the Concepts Managing realignment and Developing double-levee systems.
With this Concept description, anyone with a basic level of knowledge and/or working experience on inland lake systems can make a first order assessment.
The added value of this Concept within BwN-type projects is that it combines multi-functional use of space with utilizing the ecosystem services of wetlands. The Concept is mainly applicable in the planning and design phase.