Figure 5.2.31 – Systems to avoid animal entrance via the intersection of fencing with perimeter drainage. A: An anti-penetration grid device to the right of temporary flow evacuation devices (Photo by: Cerema); B: Fence connection to a concrete structure (Photo by: P. Fournier – GRECE); C: Non-return valve on a downspout preventing wildlife from accessing the drain (Photo by: P. Fournier – GRECE).