Using Mapsto find surface elevationsof a place.

[Geek-9pm]

What on-line Apps would give me the elevation of any location I want?

For example, I would like to plan an exit route for my family in case a flood should come in this area.  Some of the roads go thigh ground, but there're some dips along the way.  I need a way to find what places along a highway might dip below the flood plain. I t grid sing Google maps, but could not find a quick way to find elevation information.
Any ideas?
Maybe a Android App for my smartphone or iPhone?

[patio]

Many Weather sites have elevation maps.

[jenno]

Perhaps you'd be better off contacting your local environmental authority - I'm sure you have something like that? Or at least the national environment agency, whoever that may be. They would probably provide you with the most accurate information and advice.

[Geek-9pm]

One source is the geographic topology maps issued by the government, but these often are very course ant only show levels in 40foot marks. So you might be in a 35 foot hole and not it on the map.
https://education.usgs.gov/lessons/geospatialwebsites.html
I did a Google search and found there is an App that will give you a map like Google and let yu pick elevation for any point. But there are no topographical contours.
You use topographical** map to see  if yu can do a witless link from your house to grandma without going up on the roof.

**

top·o·graph·i·cal
relating to the arrangement or accurate representation of the physical features of an area.
"the topographical features of the river valley"
    (of a work of art or an artist) dealing with or depicting places (especially towns), buildings, and natural prospects in a realistic and detailed manner.

[patio]

I thought you were escaping an impending flood....not setting up wireless to Grandma's house...

[Geek-9pm]

I thought you were escaping an impending flood....not setting up wireless to Grandma's house...

How did you know?

[patio]

I do research...