Development of stormwater systems

I am very thankful to ÅForsk, who gave me the opportunity to go to the International Conference on Flood Resilience (ICFR) in Exeter, Great Britain. I am also glad that my paper about the storm water systems in Gothenburg and Mumbai got accepted to be presented at the conference. It gave me a great chance to dig deep into the development history of the stormwater system in Gothenburg. Arun Rana and I made a comparison between the Gothenburg system and the stormwater system in Mumbai and learned a lot from reading about how the systems have developed.

Stormwater inlet in street

Stormwater inlet in street

The sewer system of yesterday strongly influences the system of today and thereby also the system of tomorrow. Because stormwater and sewage structures last for a long time, and the price to reconstruct the systems are very high, the old system will have strong influence on all future decisions. Cettner, Söderholm and Viklander (2012) did write an interesting article about this in Journal of Urban Technology. This was one of the important learnings from the article writing and my conference preparation.

Conference lunch at ICFR in Exeter

Conference lunch at ICFR in Exeter
Photo: Johanna Sörensen

At the conference, I enjoyed to meet peers from all different universities, working with flood related issues in European and Asian cities. We discussed how the urbanisation and city development affect flood risk in growing cities and how climate change can aggravate the risk. We discussed how to cope with the flood risk, both from a technical and a social point of view. How far can we come with technology? What are the possibilities to protect our cities from floods? Flooding is one of the most wide-spread disasters, which can hit cities in various climates all over the world. A big concern for the future is the rising sea level, due to heating of the globe. In addition to rising sea level, we will also see more high-intense storms in many places. How can we construct our cities in a smart way to handle this? The main idea from the conference, which I took with me home, was that we will not be able to totally avoid flooding. When cities are hit by the most extreme events, there will be floods of such a magnitude that we cannot prevent them. Therefore, we need to build cities in a resilient way, with flexible systems, flexible public organisations, and flexible citizens that are prepared to cope with floods. A big flood event must not be a catastrophe for the city if the preparation is good and the technology is adaptable.

The conference gave me a complete view of ongoing flooding research. There are four main driving forces behind severe pluvial flooding in cities today: higher precipitation due to climate change, urbanisation, land use change, and higher sea level due to climate change, which can aggravate pluvial flooding. In some parts of the world, only one or the other driving force is seen, but in many places are several of these processes ongoing.

Comparison between stormwater system in Gothenburg and in Mumbai

There are several similarities between the stormwater system in Gothenburg and in Mumbai. Both systems where constructed in the late 19th century with strong influences from Great Britain. India was at the time under British control and the British engineers led important infrastructure projects in Mumbai, among those building of the early sewer system. In Gothenburg, Swedish engineers went to London to learn about the new technology and were in this way strongly influenced by the British engineers. Later on, the German engineers led the technological development in this field in Europe. Today the systems in the two cities are very different, despite the fact that the first parts where built in the same time and in the same way. After the British Empire left India, the infrastructural development of Mumbai stagnated. Things have happened since then, but at a slower pace compare to Gothenburg, were the development continued. Also the urbanisation has been considerably stronger in Mumbai, which is the biggest centre for trade and commerce in India.

Solid waste in stormwater system in Mumbai

Solid waste in stormwater system in Mumbai.

It is obvious that the problems related to flooding are much bigger in Mumbai, compared to Gothenburg. The monsoon period comes every year with heavy rainfall and the stormwater system does not have capacity enough to handle the runoff. The solid waste system in the city is not satisfactory, meaning a lot of plastic bags with solid waste lie in the watercourses instead of landfills and cause clogging of the stormwater system during the monsoon period. The municipality aims to clean all watercourses before monsoon, but often the jobs is not done careful enough to keep the watercourses free from clogging. Therefore, a better solid waste system is very important to improve flood control in Mumbai. Another problem in Mumbai is settlements on flood plains along the river. Many people in Mumbai are very poor and the city is overloaded with people. Because there is no housing for all people in Mumbai, many informal settlements are built on the floodplain and people of the floodplain lives in a high risk of flooding. As this is the poorest people in the city, they also have least possibility to protect themselves.

The ship Götheborg in Gothenburg harbour.

The ship Götheborg in Gothenburg harbour. Götheborg is a copy of a 18th century ship.
Photo: Mikael Tigerström.

One similarity between Mumbai and Gothenburg is that both cities were built on former marshland along the coast. Both cities were built as an important port and economical centre for their region. They are both low-laying and situated close to the sea, meaning the water cannot easily leave the area during storm. Gothenburg is known as one of the rainiest cities in Sweden, while Mumbai is situated in an area with monsoon climate. Both Gothenburg and Mumbai lay on the west coast with mainly westerly winds, meaning they are influenced by the sea.

Mölndal River

Mölndal River at Lackarebäcksmotet.
Photo: Johan Jonsson.

In Gothenburg the area around the central station, Gullbergsvass, is low-laying and in high risk of getting flooded. There are far-reaching plans to develop this area into a housing and shopping area in the future, despite the high flood risk from Mölndal River. When it comes to flooding, this is one of the main problems in Gothenburg, together with rising sea level and landslides along Göta River. When reading about this, I learned that high risk of flooding not always is enough argument to leave an area free from expensive investments.


Cettner, A., Söderholm, K., and Viklander, M. (2012) An Adaptive Stormwater Culture? Historical Perspectives on the Status of Stormwater within the Swedish Urban Water System. Journal of Urban Technology, 19(3), 25–40.

Model setup finished

.bat-fil for start-up of my latest four Mike21-files.

.bat-fil for start-up of my latest four Mike21-files.

Today I have finished my model setup for the next four models – Whoa! I am feel released for all forms of stress right now. Tonight I will celebrate by doing nothing and enjoy a cup of tea together with my parents at their place.
When the model simulations are finished, in three or four days, I will spends some time to gather the results. I am looking forward to see what they can tell me. In the meanwhile I will try out another model setup I have been thinking of, start to teach my new student group in hydrology and hydraulics (introductory course) and hopefully give a seminar to my colleagues at the department.

Winter meeting and career thoughts

Yesterday and today I have been to ClimBEco winter meeting in Lund. We startet with three nice presentations from PhD students in the research school, then a whole afternoon where climate negotiations were in focus and today half a day with career discussions. For me the career discussions were probably the best part, as I am going to start in ClimBEco’s mentor programme tomorrow morning. A half-day with career discussions gave me some fresh thoughts about what I want to do later on, after my PhD.

There are a few things I really like. I like to meet people and to discuss important issues. I am actually better when it comes to discuss thing that matter to me, even if it hurts sometimes when not everybody agree with you (how could it be?!), than to discuss simple things in everyday life. I like the intense and long discussions in a group where everyone is committed to find a solution. The more complex problem, the more exiting!

Another thing I like is writing. I love language and I try every day to get better. I want to get even better in finding the perfect words and nice expressions in Swedish. In Danish I try to develop my pronunciation and in English I spend a lot of time to expand and enrich my vocabulary. But I also like another side of the writing: to form a text. This basically means to scape your ideas and to find the essence of them. It is a hard work, but the process is wonderful to me.

I also like to speak in front of groups, to teach and to see others learn from me. I wish to evolve this skill more in the future, as I in my last course teaching in higher education, was given good tools for how to think about my own teaching. I have promised myself to more often give lectures, seminars, etc.. By giving lectures or seminars, you force yourself to clarify your own ideas about your research or your subject, and you get more used to talk in front of others. Moreover I would like to explore different kinds of teaching, for students, stakeholders, engineers, politicians, etc..

And of course – I like to analyse and find good solutions for a problem: in field by testing, through modelling in front of my computer or by discussing with clever partners and colleagues. My wish is to combine all these wishes and skills in a nice work in the future. Let us see what the future brings!

Thanks for a great 2013!

Dear colleagues and water friends,

2013 has been an great year in my professional life and it gave me a lot of new inspiration. I would like to thank you all for your contribution – interesting conferences, courses, nice discussions, and great cooperations. I share with you a few pictures from some of the best moments. Thanks to all of you!

Best wishes for 2014,
Johanna Sörensen

Paper submission

A few corrections before a late night paper submission.

A few corrections before a late night paper submission.

Today, I have submitted a nice paper for a conference I hopefully will attend next year. Hurray! It is time to spend some time off during the weekend.

Next week I will give a lecture in the course Advanced hydrology. I am looking forward to talk in front of students again as it is almost half a year since last time. I have promised to give a lecture urban hydrology. Probably I will tell them that the field have changed a lot over the last decade and how many great ideas that are being developed right not. It is a challange to tell them the whole story in only two hours. I guess, they have little knowledge about sewer systems and the different techologies from before and I would like to take them further. This will be fun!

Flood hazard maps available for public in Denmark

From today the flood hazard map of Denmark is available for public. It has been developed by Miljøministeriet (Danish Ministry of the Environment) in cooperation with Forsikring & Pension (The Danish Insurance Association) and can be downloaded or viewed online at The digital elevation model for Denmark has been available for a while and now the Danish Ministry of the Environment has chosen to give Danish municipalities this valuable planning tool.

400 ppm

I dessa dagar kan man läsa i tidningen att mätningarna vid Mauna Loa nu visar att vi har 400 ppm koldioxid i atmosfären. Det är skrämmande hur mycket koncentrationen stigit på få år. När jag läste till civilingenjör vid Lunds universitet (2003-2008) lärde vi oss att atmosfärens koldioxidkoncentration är 360 ppm. På bara några år har koncentrationen ökat drastiskt, vilket onekligen ger en viss respekt för människans samlade dumhet och avsaknad av framtidsperspektiv. Det är på tiden att klimatfrågan tas på allvar på alla nivåer, från varje enskild individ till stater och internationella maktcentrum. Vi måste sluta subventionera fossil förbränning och börja använda våra resurser med respekt för framtiden.

How can cities be built in a resilient and sustainable way?

In my reaserch I am focusing on urban storm water and flooding in cities. How can cities be built in a resilient and sustainable way? Due to the uncertainty of effects of climate changes in addition to the long lifetime for storm water solutions (up to 100 years), the solutions need to be adaptable to the future scenario with a long perspective. Furthermore, how can storm water solutions be a part of sustainable city development? I will try to look in to these issues during my five years at Lund University.

If you have any question you want to discuss with me or good ideas for research, you are very welcome to contact me. I would love to hear from you!

My e-mail address is

Toaletter på Jane Austens tid

Jag håller på att skriva en artikel om avloppsteknikens utveckling i Göteborg. Under detta spännande arbete, som jag hoppas kunna skriva mer om, har jag också blivit nyfiken på utvecklingen i England och föll därför över en artikel/blogg om toaletter på Jane Austens tid. Göteborgs avloppssystem, som kom på dagordningen under 1850-talet, var nämligen inspirerat av avloppssystem i engelska städer, vilket gör de engelska systemen extra intressanta för mig. I Sverige saknades kunskap, men efter flera studieresor till England kunde planer för byggnad av avloppssystem i Göteborg skrivas. Det är intressant att tänka sig att vi inte har haft vattenburna toaletter i mer än cirka 100 år. Förhållandena i Sverige såväl som i England var vidriga i städerna, med stinkande avloppsvatten på gator och bakgårdar.

Jag kan inte låta bli att visa denna fina bild som artikeln ovan länkar till. En kvinna hämtar vatten från en kran alldeles bredvid en radda soptunnor. Hygienen är förmodligen inte den bästa och detta är ändå långt senare än 1850-talet, nämligen 1931.

Kvinna hämtar vatten vid vägen, med soptunnor i bakgrunden längs väggen.

Kvinna hämtar vatten. Lägg märke till soptunnorna i bakgrunden som potentiella smittospridare. Bilden är från 1931.

Jag återkommer med mer om Göteborgs avloppssystems historia – det är något att se fram emot!