The reservoir also has an emergency spillway.

水库还设有应急溢洪道。

CNN's Paul Vercammen spent Sunday night reporting on how workers planned to reinforce the emergency spillway.

CNN 的保罗·佛卡门 (Paul Vercammen) 在周日晚上报道了工人们计划如何加固紧急溢洪道。

At Oroville, the  emergency spillway consists of a concrete weir set one foot above the maximum operating  level.

在奥罗维尔，紧急溢洪道由混凝土堰组成，位于最高运行水位上方一英尺处。

As it flowed across and down the natural hillside, water from the emergency spillway began to channelize and concentrate.

当水流过天然山坡并流下时，来自紧急溢洪道的水开始疏导和集中。

Emergency spillways are just that: intended for use only during a rare  event where it's ok to sustain some damage.

紧急溢洪道就是这样的：仅在可能造成一些损害的罕见事件中使用。

In this case, upstream  meant toward the emergency spillway structure, threatening its stability.

在这种情况下，上游意味着紧急溢洪道结构，威胁其稳定性。

The level dropped below the emergency spillway crest that night, stopping the  flow and easing fears about an imminent failure.

当天晚上，水位降至紧急溢洪道顶峰以下，导致水流停止流动， 缓解了人们对即将发生故障的担忧。

That means engineers have to be able to make conservative estimates of how much  erosion will occur when an emergency spillway engages.

这意味着工程师必须能够对紧急溢洪道启用时会发生的侵蚀程度做出保守估计。

As for the emergency spillway, the  fundamental cause of the problem was similar: a mischaracterization of the foundation material  during and after design.

至于紧急溢洪道，问题的根本原因是相似的：设计期间和之后对基础材料的错误描述。

It consisted of an  earthen embankment, a gated spillway, an emergency spillway, and a powerhouse for the turbines,   generators, and other hydroelectric equipment.

它由土堤、门控溢洪道、应急溢洪道以及涡轮机、发电机和其他水力发电设备的动力室组成。

The problem, on Sunday, inspectors found that the emergency spillway was also eroding and if it fails, it could cause flash flooding all the way to Sacramento, 75 miles away.

问题是，周日，检查人员发现紧急溢洪道也在受到侵蚀， 如果发生故障，可能会导致山洪暴发， 一直到 75 英里外的萨克拉门托。

But there was still more  rain in the forecast, and the emergency spillway was in poor condition to handle additional  flow if the reservoir were to rise again.

但预计降雨量仍然较多，而且紧急溢洪道状况不佳， 无法在水库再次上涨时处理额外的流量。

Eventually it became clear to operators that  they would have to pick a lesser evil: Increase discharges and flood the powerhouse or let the  reservoir rise above the emergency spillway.

最终，操作人员清楚地意识到，他们必须选择一个较小的害处：增加流量并淹没发电站， 或者让水库高于紧急溢洪道。

It only took a modest flow  through the emergency spillway to reveal the true geologic conditions: the hillside was  composed almost entirely of highly erodible soil and weathered rock.

只需通过紧急溢洪道的少量水流即可揭示真实的地质条件：山坡几乎完全由高度侵蚀的土壤和风化的岩石组成。

On February 12, only about a day and half  after flow over the emergency spillway began, an evacuation order was issued for downstream  residents, displacing nearly 200,000 people to higher ground.

2 月 12 日， 在紧急溢洪道开始泄洪后仅约一天半，下游居民就下达了疏散令，导致近 20 万人转移到地势较高的地方。

Operators worked to find a sweet  spot in managing these risks, limiting releases from the service spillway as much as possible  while still trying to keep the reservoir from overtopping the emergency spillway.

运营商努力寻找管理这些风险的最佳点，尽可能限制服务溢洪道的排放， 同时仍努力防止水库漫过紧急溢洪道。

The morning of February 11, about four days after the damage was  initially noticed, Lake Oroville rose above the crest of the emergency spillway  for the first time in the facility's history.

2 月 11 日上午， 即最初发现损害后约四天，奥罗维尔湖水位首次超过紧急溢洪道的顶部。

The powerhouse was further from flooding and  the transmission lines further from failing than initially thought, and they eventually ramped  up discharges from the service spillway anyway, after realizing the magnitude of the  erosion happening at the emergency spillway.

发电厂距离洪水更远，输电线路距离故障也比最初想象的更远，在意识到紧急溢洪道发生侵蚀的严重程度后，他们最终还是增加了服务溢洪道的排放量。

On the other hand, the emergency spillway  had never been tested, and operators weren't confident that it could safely release so much  water, especially after witnessing how quickly and aggressively the erosion happened on the  service spillway nearby.

另一方面， 紧急溢洪道从未经过测试，运营商对其能否安全释放如此多的水没有信心，特别是在目睹了附近服务溢洪道侵蚀的速度和严重性之后。