Station Information

DH4:
Latitude (degrees, minutes, and seconds) ......  461540  
Longitude (degrees, minutes, and seconds) .....  1221636
State Code ....................................  053
County Code ...................................  015
County Name ...................................  Cowlitz

Location Map

[Map,16K,GIF]
1998 Location Map, Castle Lake Piezometers
-- Modified from: Roeloffs, 1994, USGS WRI-94-4075

Information Table

Wells at Castle Lake Blockage
Site	Drilled in	Land elevation (feet)	Total depth (feet)	Open interval (feet)	Completed in	Remarks
I1	1983	2,656	83	2,573	1980 Debris	Inclinometer measurements have been made.
I2	1983	2,655	86	2,569	1980 Debris	Inclinometer measurements have been made.
I3	1983	2,653	97	2,556	1980 Debris	Inclinometer measurements have been made.
I4	1983	2,661	62	2,599	Pre-1980	Inclinometer measurements have been made.
P1	1983	2,655	190	2,465	1980 Debris
P2A	1983	2,628	51	2,577	1980 Debris
P2B	1983	2,629	45	2,584	1980 Debris
P3A	1983	2,629	50	2,579	1980 Debris
P3B	1983	2,628	93	2,535	Pre-1980
P4A	1983	2,585	76	2,508	1980 Debris
P4B	1983	2,584	24	2,560	1980 Debris
DH1	1990	2,600	115	2,485-2,490	1980 Debris
DH2A	1990	2,573	85	2,489-2,494	1980 Debris(?)
DH2B	1990	2,575	57	2,518-2,523	1980 Debris
DH3	1990	2,629	74	2,555-2,560	1980 Debris
DH4A	1990	2,503	123	2,381-2,384	Pre-1980
DH4B	1990	2,503	85	2,419-2,424	1980 Debris
DH4C	1990	2,503	40	2,463-2,468	1980 Debris
DH4D	1990	2,503	7	2,495-2,501	1980 Debris
DH5A	1990	2,569	82	2,504-2,509	Bedrock at 67.9 feet	In USACE publications, site DH5A referred to as DH6AZ
DH5B	1990	2,569	23	2,547-2,552	1980 Debris	In USACE publications, site DH5B referred to as DH6BZ
DH6	1990	2,572	21	2,552-2,557	Bedrock at 8.1 feet	In USACE publications, site DH6 referred to as DH5AZ
Topinka, USGS/CVO, 1998, Modified from: Roeloffs, 1994, USGS Water-Resources Investigations Report 94-4075

Sites Published In (USGS Water Resources Data Reports NOT LISTED)
-- (List not guaranteed complete) --

Roeloffs, Evelyn A., 1994,
   An Updated Numerical Simulation of the Ground-Water Flow System 
   for the Castle Lake Debris Dam, Mount St. Helens, Washington, and
   Implications of Dam Stability Against Heave:
   U.S. Geological Survey Water-Resources Investigations Report 94-4075, 80p.