All you need is a digger for a day, maybe a bulldozer, and careful planning, he said.
The worst outcome of a lot of costly earthmoving in a corner of the farm might be a dry hole.
The best would be a functioning wetland that turned a rough, wet, rubbishy area into an environmental asset, in a surprisingly short time.
They would clean up water, intercept flooding and provide habitats for indigenous plants and trees, fish and waterfowl.
“If you want to do something for the environment that will last forever, build a wetland,” Biebighauser said.
In New Zealand, as in many other developed nations, thousands of natural wetlands have been very effectively drained and eliminated.
If any of those areas were to be restored to wetlands, the underground brush or tile drains must be removed or the new wetland would never hold water.
A wildlife biologist for more than 30 years who now teaches wetland restoration out of Kentucky and has created more than 1700 wetlands in his country, South- East Asia and now NZ.
He specialises in hands-on wetland workshops, hammering a few essential construction techniques.
More than half the landowner wetland restoration attempts in the US are failures because they will not hold water, either permanently or “ephemerally”, which means at certain times during the year.
The common cause of failure is lack of sealing material such as clay, which must be tested for suitability.
The best sites are low-slope corners, waste areas, disused fields or saturated ground.
The slope must be six degrees or less and these days that can be measured with clinometer applications on smartphones.
The perimeter should be marked out with flags or tapes before the earthmoving equipment begins.
Biebighauser advocated several small wetlands rather than one big one.
He also said they should have irregular shapes, with mounds and old logs scattered around, to provide a natural look and habitats for fish and birds.
Many properly constructed and lined wetlands fill themselves with groundwater seepage, while others make take a few rainfalls to activate.
Where natural groundwater movement is to be intercepted and retained, an underground dam must be constructed with its footing on an impervious layer of rock or shale.
He said natural water levels can be raised up to 8m with this technique, and were much more preferable to above-ground dams that have to be maintained and might be subject to breaches.
“Underground dams require less money, no maintenance and will cope with storms and floods,” he said.
Where there is no suitable clay synthetic liners can be used, sandwiched between geotextiles.
The combination must be non-toxic and certified aquatic safe and a layer of soil should be replaced over the liner to hold it in place. On no occasion should machinery track over the liner.
Biebighauser has constructed wetlands in arid climates especially to hold water for livestock through very dry seasons. In that case he constructs a ramp into the water but fences the ramp sides and the bottom end to prevent livestock roaming around the wetland shores.
In some situations, landowners either want to drain a wetland or won’t build one is a fear they will be a breeding ground for mosquitoes.
That is unfounded, as mosquitoes don’t like clean water, and the dragonflies that breed in wetlands love mosquitoes, he said.
At the Whangarei seminar Northland Regional Council biodiversity specialist Lisa Forester said wetlands were the most efficient carbon sinks and came in several types – marshes, swamps, seepages, fens and bogs.
The higher fertility ones were good habitats for raupo, cabbage trees, flax, rushes, sedges and a range of native trees, like kahikatea, totara, putatea and swamp maire.
Among the birdlife she mentioned crakes, bitterns, fernbird and pukeko, as well as the waterfowl, which include shovellers, teal, black swan, grey ducks and the introduced quail, mallards and paradise ducks.
Up to 20% of Northland was once wetlands but up to 95% of those were now gone and many of the remainder are under threat from surrounding land uses, she said.
An NRC spokesman said consent wasn’t needed if an existing water course was not being altered, if flow was less than 5000 cubic metres a year and if no sediment was leaking into a water course.
“So a lot of these wetlands can be constructed without needing the consent,” the spokesman said.
