Hantering av markavvattningsföretag vid ny- och ombyggnation av vägar

Sammanfattning: This study discusses the practise of land drainage, which involves draining the soil for specific purposes as protection against excess of water. In Sweden, there are around 50,000 registered land drainage companies according to Jordbruksverket that maintain draining systems for food and forestry. The majority of the companies were established between 1900 and 1950. However, there are many excluding the 50,000, operating without registering. There is a lack of knowledge regarding these types of companies amongst engineers, Mia Hammarberg explains this in the rapport “Markavvattningsföretag – Vägledning för tillsyn, omprövning och avveckling”. The study aims to provide guidance for road and water engineers when working in a project where a land drainage company is involved. This case study was conducted with qualitative information gathering techniques such as interviews and document studies. The correspondents for the interviews are people knowledgeable in this specific area and have worked many years in the industry. The results say that there is sufficient information to be acquired for engineers, but without the knowledge and experience it is hard to comprehend what is really means and how to implement it in real life. Finding land drainage companies is relatively easy. When finding the company, the next step is to discuss the project and the future of maintaining the land drainage company. Regarding the design of a road keeping the same water flow capability, it is important to get an understanding of the bigger area and how a project will affect the situation. Water flow from fields can be assumed around 1.5 l/s-ha and the difference of water flow between hardened surface, and fields is big according to Hammarberg. The matter of re-examination of a land drainage company is dependent on the difference the project makes and if the company can handle the changes. If the new flow of water is greater than the capability of a trench, it might be preferable to re-exam. Sometimes this process is not valuable for any part and therefor an agreement can be made instead. The subject of land drainage companies can be difficult without the knowledge and experience. This case study is made for engineers and people interested in the subject, to be used and give a better picture of the process of working with land drainage companies.