The dike along a retention pond broke open Tuesday after heavy morning rains, sending a deluge of water into downtown.
City Manager Edward Dickie says about 40 homes and a dozen businesses were damaged.
Hundreds of volunteers were spending Wednesday helping to clean city streets of thick mud and debris as homeowners and business owners continue to drain their basements of floodwaters.
Dickie says some homes saw up to five feet of flooding.
He says the dike must be rebuilt. Officials say they are using sandbags in the meantime to divert any additional water into the city's storm drains and away from downtown.
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