Utilizing large woody structures (LWS) for the restoration of agriculture streams in eastern Mediterranean watersheds

In Israel, like in many other countries, many professionals in the field of river restoration offer "restoration" actions based on form and static landscaping design rather than on function, i.e., eco-hydro-morphological processes. In process-based river restoration, it is assumed that the river system maintains a dynamic complexity and changes in space and time in the stream corridors and the alluvial valley in which it flows. The flow path and the morphology of the riverbed are temporary. Herein, the focus is on the functions of the stream: transporting sediments and conveying a range of water discharges, including flooding of the riparian area. The overall goal is to increase the resilience of the ecosystem that moderates disturbances (e.g. droughts, floods) and strengthens biodiversity. The study utilizes large woody structures to renew and restore physical, chemical, and biological processes to corrected rates. We argue that the benefits of using unnatural timber within the watershed is valid for degraded agriculture streams. We constructed different LWS in Nahalal stream where the wood is part of the agricultural land uses. The source of timber is in plantations or orchards that are uprooted occasionally due to the farmer's desire to rejuvenate the plantation or orchard. We install LWS along a stream section of 2.5 km with a longitudinal gradient of 2.7%. We report on initial findings of water quality and quantity and dynamics of the LWS during winter 2023/24.