Study cases of stormwater pond’s forebays in Sweden and international state-of-art
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Övrigt, MSc
Publicerad
2023
Författare
Arce Rama, Lucía
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Stormwater pollution is one main contributor to stormwater degradation. For this reason, many countries
integrate best management practices (BMPs) to manage stormwater and reduce its pollution. Wet ponds
are one possible BMPs to implement, widely applied internationally and in Sweden. A study made in
Sweden concluded that the costs of construction are as significant as the cost of operating and
maintaining these facilities. Therefore, there is a need of having more efficient designs, thus, some
Swedish municipalities are interested in knowing more about the use of forebay. Some guidelines from
different regions and countries and previous works are investigated during the literature review part of
this thesis. Furthermore, an interview study has been made to investigate the existing design criteria in
Sweden and an analysis of the design in existing cases of pond with forebay. Lastly, an example of the
application of the design criteria in a case study is presented. Most of the local guidelines from different
regions purpose design criteria based on the area or volume of the pond or based on a rain event. Few
of them mentioned specifications about the shape of the forebay, even though the relationship between
length and width is an important parameter when it comes to hydraulic efficiency in wet ponds. The
results of the interview study made in Sweden shows that most of the design criteria applied in other
countries are being applied in the country, however, there is a lack on unification. Furthermore, based
on the analysis carried out in the studied cases in Sweden it is possible to notice that most of them do
not follow the local guidelines from different regions. Some of the cases are clear examples of the
importance of considering how is the system upstream and the importance to do maintenance of the
forebays. To apply the design criteria important factors to consider are available space and the system
upstream.
The conclusions of this work are the lack of theory when it comes to forebay design and that a
methodology that takes into account more parameters is missing. Additionally, Sweden’s design criteria
consider most of the local design criteria from different counties, however, most of the studied facilities
are not following these criteria. Furthermore, there is a lack of maintenance in the existing forebays in
Sweden.
Beskrivning
Ämne/nyckelord
BMP; forebay; maintenance; pre-treatment, stormwater management; wet ponds.