When Is A Single Span Bridge A Good Idea?
29 July 2020
Choosing which river crossing structure is best for your needs will depend on a lot of variables. But a single span bridge offers some distinct advantages and can be a smart move economically, structurally, ecologically and aesthetically.
A single span bridge stretches across the entire water course/river and doesn’t have any central piers in the water for support. It’s an ideal option when:
- Rivers have large and variable water flows
- Rivers have high riverbanks (culverts can require significant fill)
- There’s a high risk of debris or coarse sediment particles getting swept along and causing damage or blockages
- The riverbed gradient is steep, resulting in high water energy
- Riverbeds and banks are ecologically-sensitive and shouldn’t be disturbed
- Culverts and other river crossings such as fords are just not appropriate
It’s also worth remembering that a professionally-designed bridge will deliver these key benefits:
- You won’t need to modify the riverbed or banks
- Fish can swim freely
- The channel’s capacity will remain the same, reducing the risk of erosion
- It’s cost-effective in the long run thanks to low ongoing maintenance
- You won’t need to unblock the waterway after heavy rainfall
- Designed correctly, it won’t blow out in large weather events
- Typically councils prefer bridges over culverts as they’re more environmentally sensitive
- They’re less likely to involve tricky and costly resource consent conditions
- Installation can be done year-round
- You can use it regardless of the weather
Is a single span bridge what you need?
Get in touch with Bridge It NZ today to discuss your options and organise a free on-site consultation. Phone our experienced team on 0800 222 189 or email us.