D4RUNOFF NBS Library: https://d4runoff.eu/resources/

Linear drainage systems are multilayered ditches that collect, convey, slow down, infiltrate and filter surface runoff water, reducing the pressure on traditional sewage systems. They are linear in nature and have parabolic, trapezoidal, or v-shaped cross sections. They replace typical drainage elements such as concrete sewage channels and can incorporate a range of different planting strategies depending upon the site characteristics and system objectives.