A police officer said "sexist and homophobic" abuse sparked by her hairstyle led her to leave social media.
Deputy chief constable Rachel Swann made several media appearances while leading the evacuation of Whaley Bridge in August.
Some viewers mocked her on Twitter.
Ms Swann said the reaction reflected wider problems with social media and she was shocked her "mere existence could cause such a depth of feeling".
About 1,500 people were evacuated from Whaley Bridge when a dam wall at the nearby Toddbrook Reservoir was damaged in August.
Ms Swann, the senior officer in the operation, noticed comments about her on social media after she appeared before cameras at a press conference.
"Yes, I am a woman. Yes, I might have a slightly different hairstyle. Yes, I am quite small," she said.
"The bit that astounded me was I could not believe that my mere existence could cause such a depth of feeling."
She told BBC Radio Derby: "I can take a bit of banter but then it became sexist and homophobic, and really, really insulting.
"The bit that really hurt was when people said I had no standards and I was letting policing down."
Some criticised her standard issue police uniform.
"They were saying, 'she's not wearing a hat'. Often we would get advised not to wear hats - you can see our eyes, so you can gain trust."
One comment said: "Is that what a senior police officer looks likely [sic] these days??"
'Pressures of abuse'
But others - including the leader of Derbyshire County Council, Barry Lewis - jumped to her defence, saying "Be under no doubt, she saved a valley....that's what's important".
Ms Swann said it reached its nadir when a press agency "wanted to run a story on my hair" and so she took a break from Twitter.
She said: "My personal experience of the trolling and negative comments on social media are reflective of those that some people receive every day.
"Some of the comments were misogynistic and homophobic and the abuse I received has been recorded as a hate incident, in the same way it would be for the public or my officers and staff.
"In recent years, we have seen children feeling bullied by their peers through personal attacks on social media; with youngsters in some cases so desperate it has resulted in suicide due to the pressures of the abuse."
While believing more can be done by police on the issue, Ms Swann hoped her appearance in the national media showed the growing diversity in the police force - and she has returned to Twitter.
"In a funny sort of way I made my stand without meaning to. If some good comes out of that that's fine, it doesn't mean that it didn't hurt, it doesn't mean that it didn't upset me," she said.