Overview

Shadow Mountain Dam is located approximately .8 miles upstream from the alpine glacial limit. The terminal moraine is located to the south of Grand Lake and is mapped as glacial drift. The dam is located in an area where recurrent glaciers mover various distances down the valleys and left a mantle on morainal materials over the older formations. Occasional ridges of glacial debris were deposited across the valleys as end moraines when the ice receded. Shadow Mountain Dam is located in one of these moraines. The upper foundation materials are described as undifferentiated glacial moraine deposits. The heterogeneous mixture of sand, gravel, cobbles and bounders with minor amounts of silt and clay are 28 to 38 feet thick. A 13 to 17 foot thick layer of silt with sand and sandy silt, described as alluvium, lies below the undifferentiated deposits. Underneath the silt layer is the Tertiary Age North Park Formation, consisting of a conglomertitic and tuffaceous sandstone. All the material above the bedrock is described as a glacial deposit.

General

Dimensions

Hydraulics & Hydrology