HomeMy WebLinkAboutAppendix A Location Hydraulic StudyLOCATION HYDRAULIC STUDY FORM *
Dist. 12 Co. Orange Rte. P.M.
EA 15-6827 Bridge No. 55C0513
Floodplain Description:
Santa Ana River Floodplain
______
1. Description of Proposal (include any physical barriers i.e. concrete barriers,
soundwalls, etc. and design elements to minimize floodplain impacts)
City of Santa Ana proposes to widen the Fairview Street Bridge over the Santa Ana River
in order to accommodate 6 lanes; 3 lanes in each direction.
2. ADT: Current 38,544 (2017) Projected
3. Hydraulic Data: Base Flood Q100= 50,000 CFS
WSE100= n/a The flood of record, if greater than Q100:
Q= n/a CFS WSE=
Overtopping flood Q= CFS WSE=
Are NFIP maps and studies available? YES X NO
4. Is the highway location alternative within a regulatory floodway ?
YES X NO
5. Attach map with flood limits outlined showing all buildings or other improvements
within the base floodplain.
Potential Q100 backwater damages:
A. Residences? NO X YES
B. Other Bldgs? NO X YES
C. Crops? NO X YES
D. Natural and beneficial
FLOODPLAIN VALUES? NO YES X
6. Type of Traffic:
A. Emergency supply or evacuation route? NO YES X
B. Emergency vehicle access? NO YES X
C. Practicable detour available? NO YES X
D. School bus or mail route? NO YES X
7. Estimated duration of traffic interruption for 100-year event hours: 0
8. Estimated value of Q100 flood damages (if any) – moderate risk level.
A. Roadway $ 0
B Property $ 0
Total $ 0
9. Assessment of Level of Risk Low X
Moderate
High
For High Risk projects, during design phase, additional Design Study Risk Analysis
May be necessary to determine design alternative.
Signature – Dist. Hydraulic Engineer Date _____
(Item numbers 3,4,5,7,9)
Is there any longitudinal encroachment, significant encroachment, or any support of
incompatible
Floodplain development? NO X YES
If yes, provide evaluation and discussion of practicability of alternatives in accordance
with 23 CFR 650.113
Information developed to comply with the Federal requirement for the Location
Hydraulic Study shall be retained in the project files.
Signature –Project Engineer Date
(Item numbers 1,2,6,8)
* Same as Figure 804.7A Technical Information for Location Hydraulic Study located in
Chapter 804 of the Highway Design Manual