1-02CW372 Supplemental Data

• Case Number: 02CW0372
• Lake Name: Jewell Mountain Lake
• Watershed: South Platte River
• Water Division: 1
• Water District: 6
• County: Jefferson
• NLL App - Doc Type: Supplemental Data

Natural Lake Level Recommendation
COBOS's natural lake level recommendation is for an elevation of 6,263 feet.
Land Status Review
Lake Name
Surface (acres)
Land Ownership
% Private
% Public
Jewell Mountain Lake
7
0 %
100 %
100% of the lake is located on COBOS lands managed by the City of Boulder.
Biological Data
The CDOW has conducted field surveys of the fishery /natural environment resources on this
lake and have found a natural environment that can be preserved. As reported for this lake in
the December 10, 2001 letter to the CWCB, Natural Environment Surveys indicate that the lake
environment is in stable condition. In 1999, the CDOW sampled Jewel Mountain Lake at the
request of Boulder Open Space staff. We set five nets (two gill nets and three trap nets) for a
period of 18 hours on August 11, 1999. A total of 51 painted turtles were collected as well as one
tiger salamander larvae. It is assumed that no fish are present in Jewel Mountain Lake because
none were collected in the nets and fish and tiger salamanders are rarely found together. Based
on our sampling efforts at Jewel Mountain Lake (See CDOW Environment Survey in Appendix
B), the CDOW is of the opinion that a natural environment exists at this lake and this natural
environment is worthy of consideration for protection with a CWCB natural lake level water
right.
City of Boulder Open Space has provided us with information regarding the size of the lake
(6.87 acres) and the elevation of the historic high water line (6263.17 feet). Seasonal
evaporation appears to reduce the elevation by as much as five feet in extreme years but the
normal amount of evaporation is typically approximately two feet. Given the unique nature of
this lake from a statewide perspective, the Division of Wildlife believes that an elevation of 6261
feet is the minimum amount of water necessary needed to preserve the natural environment of
Jewel Mountain Lake to a reasonable degree. The estimated lake volume at this elevation is 28.9
acre feet.(See CDOW Environment Survey in Appendix B).
Field Survey Data
CDOW staff visited the lake on September 20, 2001. Appendix B contains copies of field data
collected for this proposed natural lake.
Existing Water Right Information
Staff has analyzed the water rights tabulation and consulted with the Division Engineer Office to
identify any potential water availability problems. There are no decreed water rights on this lake.
Based on this analysis staff has determined that water is available for appropriation Jewell
Mountain Lake, to preserve the natural environment to a reasonable degree without limiting or
foreclosing the exercise of valid existing water rights.