|
Incident ID |
SD00029-3414 |
|
Dam Name |
ALVIN |
|
Downstream Hazard Potential |
L |
|
State |
SD |
|
Incident Date |
01/01/2019 |
|
Incident Type |
Non-failure |
|
Incident Driver |
Hydrologic/flooding |
|
Incident Mechanism 1 |
Spillway Chute Failure |
|
Incident Mechanism 2 |
Slope Stability |
|
Incident Mechanism 3 |
|
|
Incident Description |
Multiple high flow events in 2019 damaged primary spillway with portion of spillway wall collapsing and caused embankment sloughing adjacent to primary spillway and stilling basin. |
|
Named Hydrologic Event |
|
|
EAP Enacted (Y/N) due to Incident |
No |
|
Fatalities (Number) |
0 |
|
Number of People Evacuated |
unknown |
|
Number of Habitable Structures Evacuated |
unknown |
|
Number of Habitable Structures Flooded |
unknown |
|
Other Infrastructure Impacts |
Roads |
|
Economic Damages (in $) |
|
|
Volume released at failure (ac-ft) |
|
|
Response |
Owner did some stabilization work on sloughing and hired an engineering consultant to do additional analysis |
|
Additional Remarks or Updates |
County road downstream of dam was closed for several days in May 2019. Downstream highway culverts have limited capacity so during high flow event water backs up in the stilling basin, primary spillway, and against embankment area adjacent to primary spillway and stilling basin. |
|
Incident Time |
|
|
Incident Duration |
|
|
Incident Report Produced |
|
|
Information Sources |
SD Dam Safety |
|
Owner Type |
S |
|
Dam Type |
RE |
|
Primary Purpose(s) |
CR |
|
EAP |
NR |
|
Year Completed |
1954 |
|
Year Modified |
1994 |
|
Dam Height |
36 ft |
|
Max Storage (ac-ft) |
2150 ac-ft |
|
Surface Area (acres) |
46 acres |
|
River Name |
NINE MILE CREEK |
|
Latitude |
43.44 |
|
Longitude |
-96.6083 |
|
Regulatory Agency(ies) |
DENR |
|
NID Number |
SD00029 |
|
Attachments |
|
