When Is A Single Span Bridge A Good Idea?

29 July 2020
When Is A Single Span Bridge A Good Idea?
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.