Stadsgrachten

Aaf Verkade, Advisor on Urban Canals, helps communities and organisations understand and care for the living waterways of Leiden and beyond. Her work focuses on the “blue urban nature” beneath and around city canals, and on keeping these waters clean and welcoming for people and wildlife. Drawing on years of local experience and authorised snorkel-based fish monitoring, Aaf investigates aquatic habitats and the species that live in them, including fish, crayfish, crabs and turtles.

Her services include canal advice, fish and castle-moat research, and guidance on monitoring urban fish populations. She also organises excursions along the canals, gives talks, and creates water-themed theatre for visitors at sites such as mills, castles and gardens. Aaf works with residents on clean-up activities, from removing litter underwater to collecting floating debris, and supports nature-friendly projects such as underwater habitats for bullheads. Through practical research and engaging activities, she connects residents, public authorities and other local stakeholders, helping them discover urban waterways and take part in caring for them.