[help] i need help to lower the water level

Hello, i need help to lower the water level.
I’ve look a file called: water.xml but I do not know what to touch to lower the level of the water.

water.xml:

<?xml version="1" encoding = "UTF-8"?>
<WaterData>
  <WaterQuads>
<Item>
      <minX value="-6000" />
      <maxX value="6000" />
      <minY value="-6000" />
      <maxY value="6000" />
      <Type value="0" />
      <IsInvisible value="false" />
      <HasLimitedDepth value="false" />
      <z value="0" />
      <a1 value="26" />
      <a2 value="26" />
      <a3 value="26" />
      <a4 value="26" />
      <NoStencil value="false" />
</Item>
  </WaterQuads>
</WaterData>

Just play around with it and you can probaly figure it out

how can we stream water.xml ?