Referencing and Analyzing Dams with the National Hydrography
Dataset Jeff Simley, U.S. Geological Survey Bill Smith, U.S.
Geological Survey Slide 2 You're visitor 214447 since 01/25/1999
and 10 for today 08/04/2006 Slide 3 Dam Network upstream of dam
blocked by dam Upstream navigation start Red: Everything upstream
Slide 4 Slide 5 90 ft. NID dam location Edited dam location Indexed
dam location Lake Dam address: Reach: 14010001002651 Measure:
99.929218 Slide 6 NID dam location is reasonable Slide 7 Correct
location for purposes of the NHD Slide 8 Look at dam name and river
name to determine where the dam belongs NID location Slide 9 Look
at NHD name and flow Slide 10 Moved dam here to get proper indexing
result Slide 11 NID Dam location Assumed correct dam location Slide
12 NID location Assumed location Use name to aide decision Slide 13
Easily made assumption of correct dam location based on graphics
Use name to confirm Slide 14 Assume location simply by stream name
Assume location at nearest spot with only stream name for guidance
Slide 15 No evidence of a dam Slide 16 Slide 17 No evidence of dam
Slide 18 Slide 19 Non-indexable Dam location Slide 20 NID dam right
on stream looks like a hit, but no evidence of a dam in imagery
Slide 21 Three NID dams with no evidence in imagery Slide 22 Assume
dam belongs on lake NID location Indexed location Lake Slide 23 NID
location almost right on stream, but no evidence dam, except
possibly nearby lakes Slide 24 Dam NID location Slide 25 Dam and
lake not connected to NHD network No point in indexing this, but
may want to improve location of dam Slide 26 Cant find the lake
this dam belongs to Slide 27 Make assumption of dam location based
on name and graphics Slide 28 Actually have dam in NHD to confirm
location Slide 29 Not enough information in location or stream name
to Make decision Not enough information in location or stream name
to make decision on correct location Slide 30 Dam near wrong
flowline for proper position Slide 31 Dam has two outlets in NHD
Slide 32 Dam has two outlets in NHD Slide 33 Dam has two outlets in
NHD Slide 34 Dam has two outlets on map, but only one in NHD Slide
35 Two streams impounded by one dam Slide 36 Two NID dams Two NHD
flowlines Unclear what second dam does Slide 37 Question of where
exactly to index dams Slide 38 Lake has two outlets Slide 39 Create
dummy dam Move NID dam Slide 40 Moved dam and indexed Created dummy
dam and indexed Slide 41 Use flow direction to determine dam
location at just one outlet point Slide 42 Two outlets, but only
one dam Slide 43 Two dams represented by one NID dam Slide 44
Corrected dam location Dummy dam Non-indexable dam Slide 45
Indexing results with 50 ft tolerance All but non-connected dams
have indexed Slide 46 Properly indexed dams Slide 47 Dams on
Colorado River system upstream of Blue River confluence Slide 48
Colorado River system dams with normal storage of over 1,000
acre-feet Slide 49 Dams upstream of Blue River confluence with
normal storage over 2,000 acre-feet Slide 50 Dams upstream of Blue
River confluence Built before 1960
