Making water is not as easy as it seems to someone who is learning how to map. Let me show you not o­nly how to create basic water, but then how to make it rise and fall.

1. After constructing the area that will be holding the water, create a water brush using the texture of your choice (I of course suggest that you use the water texture, but the choice is clearly yours).

Make the texture slightly larger than the holding area. This is neccessary to avoid odd looking edges o­n the walls of the pool. When the water is rendered, you will be able to see the edges of the water and in our case, this is undesirable.

Also, be sure to make the brush the same height as you wish the water to rise. You don't want there to be a lack of water at the bottom of your pool.

2. Select the water brush and ope the texture editor. Mark the check box under content flags labeled water. This will make the brush a non-solid.

In some cases, you may wish to check the boxes for warp to make the water wavey or flowing, but I will not get into that here.

3. Turn the brush into func_water and open the entity editor.

Give the water an angle of up since we want the water to rise when we trigger it.

Give it a targetname of water1.

Give the water a lip equal to the amount of water already in the room plus a small amount (I usually oversize all my water by about 8 units) to avoid allow the water's edge from being seen at the bottom of the pool.

Give it a wait time of 2 (or appropriate time for your map). This will cause the water to wait for 2 seconds before returning back to it's original state.

4. Now we need to create a trigger that will cause the water to rise. I thought in this case we would create a lever o­n the wall.

Create the appropriate brush to act as the lever somewhere the player can reach.

Turn it into a func_button and open the entity editor.

Give it a target of water1 and an angle of down.

That should do it.

If you want the water to flow, open the texture editor, uncheck the box for warp and check the box for flowing. Place the speed of flow in the value box and adjust the direction by adjusting the rotation.