A high water mark is a location that symbolizes a body of water's highest rise over land. A high water mark is frequently the consequence of a flood, but it can also represent an all-time high, an annual high (the maximum level to which water reached that year), or the high point for any other time division. High waters can cause damage by way of erosion, flooding, or other hazards. The U.S. Geological Survey (USGS) defines a high water mark as "a surface formed by the highest recorded tide or flood." The term is most commonly used to describe locations on coastlines where higher tides or floods have caused sediment to be deposited out of reach of the low tide line, thus raising the sea wall or other shore protection structure above its normal position. In geology, high waters are areas where rock has been exposed by erosion or where caves or holes have been dug into the earth's surface. High waters may also refer to regions of extremely high ground pressure that can cause rocks to be dislodged or torn from their places in the Earth's crust. High waters can also be found inside bodies of water. Here, the term refers to areas where the water's surface is at a height greater than anywhere else within the body of water. This happens when water levels are high enough to overflow its banks, causing inland flooding. On lakes and oceans, high waters can occur after significant rainstorms or during spring runoff seasons when the snowpack melts rapidly.