The River Calder Restoration Project

Reviving the riparian ecosystem by fostering new native woodland habitat along the River Calder, enhancing biodiversity and protecting against climate change impacts.

This project was supported by the NatureScot Biodiversity Challenge Fund.

The River Calder, an upland tributary of the Spey, is undergoing a transformation. An ambitious, landscape scale project to restore native riparian woodland was delivered in 2021/2022 and aims to establish up to 15 hectares of riparian woodland along 3.5 km of the Calder. This project complements another project delivered in 2020 which introduced Large Woody Structures into the river channel. (LINK)

This project is an example of using nature-based solutions to future-proof against the impacts of climate change while significantly expanding and improving habitat for aquatic and terrestrial species. The approach included installing deer fencing, planting native trees, and promoting natural regeneration.

Project Delivery: What did we do?

The project was completed in March 2021. Here are the main features of this project:

1. Deer Fencing Installed

To protect young trees from browsing by deer and sheep, approximately 5.5 kilometers of deer fencing and seven water gates were installed. As the Calder is a large, spatey river, a robust, innovative design was required for the water gates. Swing fencing was used on areas of the flood plain to avoid flood damage.

2. Tree Planting

Over 15,000 trees made up of a diverse mix of native tree species were planted, to kick-start re-establishment of natural woodland.

3. Natural Regeneration

Alongside planting, natural regrowth is now occurring within the protected areas. There are seed sources from older trees in the glen and substantial regeneration of pioneer species such as birch and rowan is taking hold.

What are the Benefits of this Project?

1. An increase in availability and diversity of habitat

The project has diversified the habitat available in the area, creating new riparian woodland which not only benefits terrestrial species but will also, over time, improve in-stream habitat through addition of deadwood and nutrients to the river, and the stabilising of the banks by tree root systems. By creating up to 15 hectares of new woodland in three separate enclosures, a new native woodland corridor will be formed along the glen, allowing for enhanced movement of bird, mammal and invertebrate species, crucial for ecological connectivity and resilience against climate change.

2. Shading to keep water cool

As our summers continue to get hotter, more woodland along our river banks is going to be essential to safeguard threatened species which are susceptible to heat stress and even heat-induced mortality, such as Atlantic salmon and trout. The shade provided by the new woodland will help to regulate water temperature, and bankside trees along with deadwood in the river will create cooler refuge areas for fish to escape to in peak temperature conditions.

3. Natural Flood Management

Woodland can act as a sponge during heavy rainfall, holding water for longer in this upland glen and smoothing out peak flows. This contributes to reducing the risk of flooding downstream, protecting land and communities along the Spey.