What is a wall called which is placed in an open channel to measure water flow?

What was the advantages and disadvantages of building an entirely new city for a states capital? What kind of building where in santa ines? Where does the Ubangi river flow through? What are seven man made wonders of the world? What city does the Missouri river meet the Mississippi river? What river flows through strabane? Where are the ozark mts? How far is it from fall creek falls to nashville? How Does the Mississippi Flood? How much water falls down High Force Waterfall? Is the Loch Ness monster in the Bermuda triangle? How much are sea urchins worth? Has anyone been hurt at cedar point amusement park? What is ungauged catchment? What are the names of the twins in journey to the river sea? Did the settlers have succeeded in turning land in the amazon basin into productive permane? In which state can Wyandotte Cave be found? Which river is located nearest number 8? Is there water under the empire state building? In which direction is the closest ocean to sugar land?