《后汉书·列传·西羌传》
不久又拦截河水疏通渠道搞屯田，每年内地各郡省下的费用达一亿。
既而激河浚渠，为屯田，省内郡费岁一亿计。
Soon, the river was intercepted and the canals were dredged for farming. The annual expenses of the counties in the interior reached 100 million yuan.
<s>[INST] 请提供这段文言文的现代汉语解释: 既而激河浚渠，为屯田，省内郡费岁一亿计。 [/INST] 不久又拦截河水疏通渠道搞屯田，每年内地各郡省下的费用达一亿。</s>
请提供这段文言文的现代汉语解释: 既而激河浚渠，为屯田，省内郡费岁一亿计。
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不久又拦截河水疏通渠道搞屯田，每年内地各郡省下的费用达一亿。
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