Best practices from around the world

In this section, we will present 3 exemplary case studies from around the world to inspire our future vision and contingency plan for Nyhavna.

1. The Netherlands

The Netherlands is a fairly small but densely populated country in Northwestern Europe. It is a low-lying coastal country touching the North Sea and much of the land has been reclaimed from the sea by dredging the seafloor and artificially creating land, also called polders, for people to live on. As a result, the Netherlands has been dealing with floods that compromise its infrastructure and quality of life for residents. More than half the country is susceptible to flooding from the sea and connected waterways. The country has had a Delta Committee since the 1950’s when the Netherlands experienced a massive flood and thousands of people died. Moreover, the country faces many flood risks and freshwater management challenges and as a result the government came up with a water policy document called the National Water Plan for the years 2016-2021. In it, they outline how they are going to keep the coastline of the country safe from flooding and protect the coast for future generations while creating recreational opportunities for the shoreline (Koshy, M, 2023; Nillesen, 2023).

For example, the country has implemented measures to shorten the coastline so it’s more easily manageable, they also installed dikes, built seawalls and implemented dune enhancement to improve safety standards for the coastal communities. To increase the ecological resilience while improving the quality of life, the Dutch also started to implement transitional natural buffers that have more scenic and spatial qualities as opposed to the old hard infrastructure projects. For example, instead of building defensive seawalls, the Netherlands adopted a softer approach to coastal preservation and protection. These green infrastructure projects include intermediate or natural edges with transitional, gradual and sloppy access to the water which increases public access and provides leisure activities. It also increases the scenic aspect of the waterfront and creates a natural buffer between the water and the residences that are located further away. (Fig.18)

This could be in the form of a natural or artificial dune formation, living shorelines, wetlands preservation or estuary protection. (Fig.19) This approach provides a greater level of protection against big waves, it leads to sediment accretion which further smooths out the wake and it provides habitat for marine life and vegetation and other animal species such as birds and insects, and it allows people to interact with the waterfront rather than being walled off from it.

2. Copenhagen, Denmark

Copenhagen is the capital of Denmark, a small coastal country in Scandinavia. Rainy, gray weather is pretty common throughout all of the season. In 2011, the city experienced a cloudburst, i.e. an excessive amount of rainfall in less than 24 hours, which led to massive floods in the city causing damage and structural failure to the city’s infrastructure. As a result, the city adopted a Cloudburst Management Plan. The document serves to investigate further areas of risk, collects data, includes modeling and mapping techniques to identify the risks, it provides a cost vs. benefit analysis, it focuses on design and quality of the blue-green structures and provides a summary of economic benefits (Oppla, n.d.).

The goal of the plan is to reduce peak flood, increase infiltration and storage capacity, reduce runoff, increase biodiversity and provide people with higher quality green spaces that serve multiple functions. One such example can be seen below (Fig.20), where the Sønderboulevard street is used as a green public space for leisure activities during the dry season, and during extreme rain events it acts as a water reservoir. The permeable surface of the park area allows the water to percolate downward instead of causing a street runoff and flooding the streets. A similar example on a much smaller scale can be seen in Figure 21, where the space between parking lots are used as a catchment area for excess rainfall and provide habitat for plants which beautify the area.

3. Virginia

Based on a scientific agreement reported by the Intergovernmental Panel on Climate Change, the average global sea level rose at an average rate of 1.8 mm per year from 1961 to 2003, which is proceeding more every year (IPCC). In Virginia state in the U.S.A, flooding was not a concern in the past, it is now expanding the flood possibilities due to sea level rise, global warming, and climate change. Based on the long-term water level measurements from 1961 to 2003 local sea level rise in Virginia averages around 3.6 to 7 mm per year. (1.8 to 2.30 feet per century).(Boon et al., 2009)

This state seems to be so vulnerable to flooding in the future due to hurricanes and northeasters. Uncontrollable sea level rise in the long term will inundate all the infrastructures such as transportation, military installations, and agriculture and damage the marine ecosystem, human health, and recreation. So they started a monthly and yearly measurement of the sea level rise that could provide enormous amounts of information for the government and other related organizations to be prepared and cautious about the phenomenon and consider the variety of criteria to prevent flooding and the following damages. (Boon et al., 2009)

The Virginia Institution of Marine Science has used sophisticated dynamic computer models to create models and figures for simulating floods in the different locations of the land, as illustrated in figure 22 and 23. As a result of technological development, new methods like airborne Light Detection and Ranging have been used to delineate coastal topography, and also the new technology in forecasting weather like National Weather Service was so effective. Combining the measured data and modeled information helped to be more confident to even go further and try to have a more trustworthy and accurate future model prediction.

The methods used in Virginia such as measuring and tracking the sea level rise and using new technology and supercomputers for complex analysis helped this state to be more prepared for the future hazards like flooding. (Boon et al., 2009)