Beja Dam, Latvia

River Alūksne is once again free-flowing thanks to the removal of the Beja Dam

River Alūksne is once again free-flowing thanks to the removal of the Beja Dam
The River Beja is a small, fast flowing river in the Eastern part of Latvia (Figure 1). It is 24 km long, flows out from Lake Alūksne and enters River Pededze, and its watershed is 120 km². The river is in the “Daugava” river basin, which is one of the four main river basins in the country. It is named after Beja, a small village, and a nearby protected area, the “Beja Forests”. The river is also known as Alūksne, which is the name of a nearby city and a lake close to where the river springs from.

Figure 1. Location of the Beja Dam at River Alūksne in northeastern Latvia

River Alūksne was fragmented by Beja Dam, which was the only barrier to fish migration, but was blocking around 20 km of the river corridor. In recent years, several municipality and state funded fish monitoring projects have taken place in River Alūksne watershed. The results showed that the river is an important habitat for endangered freshwater fish species like brown trout (Salmo trutta fario), grayling (Thymallus thymallus), European chub (Leuciscus cephalus), burbot (Lota lota), and European brook lamprey (Lampetra planeri). It was also evident that suitable habitat for these species, during all ontogenetic stages, were available both above and below the dam. However, brown trout and grayling populations were present only below the dam, at the lower half of the river which runs into the larger River Pededze basin (1600 km²). Thus, roughly half of the suitable habitat in River Alūksne was not available to these endangered migratory freshwater fish species. In addition, field observations and intel from local anglers’ clubs indicated that the Beja reservoir above the dam used to warm up considerably during the summer time (water temperatures were reaching up to 23°C) making large areas above and below the dam inhospitable for ecologically sensitive riverine fish and invertebrate species.

The Beja Dam
The Beja Dam was a ~4-m-high and ~6-m-wide wooden sluice (Figure 2) and a total barrier to fish migration. It was situated under a bridge, and the bridge apron was causing an elevation in water level and thus being an additional barrier to fish migration (Figure 2).

Figure 2. The Beja Dam in March 2021 © Magda Jentgena

The Beja Dam belonged to the Vietinghoff family in the 19^th century, but it was passed on to several owners since. After Latvia gained its independence in 1918, the dam remained operational to facilitate water to a sawmill that was built next to it. Around 1950, its purpose was shifted and became a small hydropower station. Around 1970 the water from the reservoir was removed, but around 1980 the water level was raised again to facilitate duck hunting, and remained at this state to this day (Figure 3). Lately, the dam had no function as there is no mill or hydropower station in place. It was also ownerless, and in critical condition (Figure 4) and could cause floodings to areas downstream.

Figure 3. The Beja reservoir above the dam in March 2021 © Valdis Skudre

Figure 4. (left) Upstream view of the Beja Dam in July 2021, and (right) cracks on the bridge above the Beja Dam caused by the water pressure © Magda Jentgena

Dam removal
In Latvia, once an object is in a state of emergency, the local municipality must take action by either fixing or removing it so it does not pose a threat to the public. This was the key argument in favor of the Beja Dam removal, given that there was no available funding to repair the structure.

The project started in 2021 with the preparatory works which lasted till the following year. The lack of an owner gave the initial impression that the project could move forward easily, but in the end that caused more difficulties. The road authority who owned the bridge crossing over the dam refused to claim ownership and take the responsibility for the dam, even though they were interested in its removal because of the damages caused to the structure by the water level/pressure. In the end, the local construction authority agreed to let the removal move forward providing that all the local landowners agreed to it. Despite the original support to the removal from all the landowners, one of them changed his mind at a later phase forcing the project to pause temporarily.

When consent was obtained from all parties and following the expert evaluation regarding the status of the dam, the process to acquire all the necessary paperwork began, which lasted almost a year. The permission to lower the water level was granted in May 2023 and the works lasted around 2 weeks, as the process proceeded gradually and under controlled conditions. During this first phase, the wooden structures were removed, while the bridge apron remained (Figures 5 & 6).

Figure 5. Removal works at the Beja Dam in May 2023 to lower the water level © Valdis Skudre

Figure 6. Beja Dam in August 2023 after the first phase of the removal works © Magda Jentgena

After the water level was lowered, the in-river works were paused to let the accumulated sediment to be mobilized and removed naturally, a process that occurred in less than two months (Figures 7 & 8).

Figure 7. The Beja reservoir (left) before (April 2021) and (right) after (June 2023) the water level was lowered in May 2023 © Magda Jentgena

Figure 8. The River Beja right upstream the dam (up) before (14 May 2023) and (down) after (15 May 2023) the water level was lowered © Valdis Skudre

A year later, in early June 2024, the removal of the Beja Dam was complete by cutting out a piece of the bridge apron (Figures 9 & 10). In specific, the middle, 3-m-wide part was removed and subsequently filled with gravel, and the riverbed was also restored (Figure 10).

Figure 9. Removal works of the bridge apron that concluded the demolition of the Beja Dam project © Magda JentgenaRemoval works of the bridge apron that concluded the demolition of the Beja Dam project © Magda Jentgena

Figure 10. The removal site after the complete demolition of the Beja Dam in June 2024 © Magda Jentgena

Figure 11. Riverbed restoration in June 2024, following the completion of the removal works of the Beja Dam © Magda Jentgena

The project was implemented by Pasaules Dabas Fonds and mainly financed by Open Rivers Programme, which provided 99500€. This amount covered all the construction costs, and the monitoring, as well as some part of the project management. The originally estimated cost for the project management and the communications was underestimated and thus part of it was covered by a corporate partnership that Pasaules Dabas Fonds has with a local water company called “Mangaļi”.

Challenges
The main challenge was the bureaucracy around this project. As this was the first dam removal of this kind in Latvia, the construction authority was not sure of the process (e.g., what paperwork was needed), since any legislation relevant to removing dams is lacking at the moment. This fact along with the weather conditions and the fish migration periods during which in-river works were prevented prolonged the project.

An additional challenge that had to be overcome was the opposition from a local landowner. This particular individual was not against the removal per se, but to the alteration of the scenery he was used to, as he had lived his whole life by the dam. He had also invested in releasing fish in the pond behind the dam in the past, and thus he had an additional interest in keeping the dam in place. In the end, his reluctance was overcome and he supported the dam demolition.

Ecological and community benefits
The removal of the Beja Dam opened the upper half of the River Alūksne to fish and other aquatic animal migration. It is expected that the populations of the endangered riverine fish species will be enhanced in the whole Pededze basin, as Alūksne is its largest tributary that provides suitable spawning grounds for many species, like brown trout and grayling. In fact, some local fishermen have already observed trout travelling upstream from where the barrier used to be.

In addition, by removing the Beja Dam, the natural river flow has been restored and the water temperature has decreased to normal/typical values for fast-flowing rivers. The river has also returned back to its natural state (e.g., rapids have formed above the removal site) by restoring the hydromorphological processes (e.g., sedimentation) and ensuring habitat connectivity. On a broader perspective, the project contributed to reaching Good Ecological Status as defined in the European Water Framework directive (WFD), since unhindered flow regime and habitat connectivity are important measurables when determining ecological quality status for a given waterbody.

Prior to the dam removal, some locals were worried about the impacts on the bridge’s stability, but this was carefully calculated and the bridge was never at risk. In fact, the bridge is now safer, since the water reservoir behind the dam is gone and with it the significant pressure from the large water volumes. Also, the flood risk and any impact it could have downstream has been significantly reduced.

The barrier removal and the river restoration efforts will provide the opportunity for recreational activities, like the creation of a kayaking route. Kayaking/boating is a very popular activity in Latvia during the summer time, but dams prevent a safe and unhindered execution. The municipality in cooperation with local businesses has already developed several popular kayaking routes on River Pededze and has expressed interest in including River Alūksne in its network of routes. Additionally, hiking routes along the river could be developed, and several excursions and events have already been organized along the river to show the effects of the dam removal. For instance, a live interview was organized by World Fish Migration Foundation and WWF Netherlands in cooperation with Pasaules Dabas Fonds and support by Open Rivers Programme from the newly restored site (Video 1).

Video 1. Interview with Magda Jentgena, Water Programme Manager at Pasaules Dabas Fonds, from the restored site at River Alūksne on 13 September 2024

Finally, the expected enhanced fish populations will also create the opportunity for fishing tourism to develop in the area, as well as boost the interest of local anglers. Managing river recreational fisheries with a focus on sustainable catch and release salmonid fishing is becoming increasingly popular with local and visiting anglers all around northeastern Europe and similar practices could be implemented in the restored River Alūksne.

Monitoring surveys are conducted following the dam removal to record the effects of the project. The monitoring will continue through 2025.

Before & After photo pair

The removal site at: (left) before and (right) after the demolition of the Beja Dam © (left) Valdis Skudre, (right) Magda Jentgena

With many thanks to Magda Jentgena for providing the information and the visuals presented herein.

Prepared by Foivos A. Mouchlianitis