The average gestation period for rabbits is 31 days; however, it can vary from 29 to 35 days. Does should be pregnancy-checked 14 days after mating. If not pregnant, they can be re-bred immediately.
Buttresses and an arch of the Roselend Dam in France. A buttress dam or hollow dam is a dam with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of buttresses or supports.The dam wall may be straight or curved. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the ground.ater pushes against the dam, but the buttresses are inflexible and prevent the dam from falling over. Buttress or hollow gravity dams were originally built to retain water for irrigation or mining in areas of scarce or expensive resources but cheap labour.
Normally buttress dams are made of concrete and feature a series braces called buttresses along the downstream side of the dam to prevent the natural flow of water. The Daniel-Johnson Dam in Quebec, Canada is a multiple arch buttress dam.