"以堤防堵挡" can be translated into English as "to block or dam up with dikes" or, more contextually specific, "to use dikes for blocking and containment".
Here's a breakdown:
"堤防" (dīfáng) means "dike" or "levee," which is a structure built to prevent flooding by containing water.
"堵挡" (dǔdǎng) means "to block" or "to hold back."
So, combining these, the phrase emphasizes using dikes as a means to block or contain water flow.
For a more natural-sounding sentence in English, you might say:
"They used dikes to block and contain the flooding."
"Dikes were employed to prevent the overflow of water."