Bemböle mill ruins and riverbed successfully restored

In the 18th century, there were two watermills - an upper and lower mill - on the Glomsinjoki rapids at Bemböle in Espoo. They stopped operating in 1929, when the wooden parts of the mill burned down in a fire. The remains of the wooden and stone mills in the original rapids environment include the ruins of the grey granite mill building, some dam and mill structures, downstream riverbed support structures and the mill pond behind the upper mill. In the now-completed project, the lower mill in the river was restored and the old cross country ski track bridge was dismantled. Water flow was restored over a span of approximately 60 metres.

Nationally protected mill ruins in a valuable nature area

Cereals from Bemböle, Karvasbacka, Gloms and Lövkulla were ground at the River Glomsinjoki rapids already at the end of the 16th century. A parish map from 1750 shows two watermills used during the spring and autumn floods. The old mills had already deteriorated at that time. They were replaced by a new vertical-axle mill, which was later replaced with a water wheel mill. In addition to the mill building, the watermill included a dam and a mill pond formed behind the dam.

The Bemböle mill ruins are protected by the Antiquities Act (295/1963), and they are listed as a nationally significant archaeological site (VARK). There are 12 such sites in Espoo. The Act prohibits the digging, covering, altering, damaging, removing and any other tampering of an archaeological site.

The mill ruins area is also protected by the Nature Conservation Act (1096/1996) as a priority habitat for specially protected species due to the Bembidion monticola ground beetle that is endemic to this area. The River Glomsinjoki stream valley is the only known habitat of Bembidion monticola in Finland. Nature and conservation values were taken into consideration in the restoration process. The restoration project was carried out in accordance with the instructions issued by experts of the ELY Centre and Finnish Environment Institute’s Coleoptera working group.

Successful restoration

The aim of restoring the mill ruins was to prevent their destruction, for example, by replacing missing keystones to support wall structures and employing old masonry techniques to relay and reinforce sections of the wall that had collapsed or were in danger of collapsing.  The wall surface was protected with a layer of plaster and metal mesh, which was covered with a growth substrate and meadow matting. The purpose of the protective layer is to prevent water from entering the wall structures, thus preventing them from deteriorating in the future. The worst collapsed sections were relaid to prevent further collapse. The purpose of the restoration was not to restore the ruins, but to preserve them.

In connection with the restoration, water flow in the riverbed was restored under the direction of running water experts at the ELY Centre. During the restoration, stones were added to the riverbed to dam and guide the water, thus creating eddies where trout can rest and gather their strength on their migration upstream to Lake Bodominjärvi. The stones also offer shelter to trout fry.

The Public Works Department was responsible for the planning and funding of the restoration project. Espoo City Museum was responsible for the supervision of antiquities in planning. The project was carried out by IKJ Rakennus Oy, and it was completed according to plan, both on schedule and within the set budget. The magnificent end result of the restoration honours this site of historical significance. 

More information:

Mikael Ahlfors
landscape horticulturist
Espoon kaupunki, kaupunkitekniikan keskus
mikael.ahlfors@espoo.fi

Tryggve Gestrin
curator
KAMU Espoo City Museum
0505666105
tryggve.gestrin@espoo.fi 

Espoo has 12 nationally significant archaeological sites

Erityisesti suojeltavien lajien esiintymispaikan muuttaminen (in Finnish)

Bemböle kvarnar (In Swedish)