FLOOD07275

• County: Costilla
• Community: Costilla County
• Stream Name: Trinchera Creek, Costilla Creek
• Basin: Rio Grande
• Title: Floodplain Information Report
• Date: 3/1/1994
• Prepared For: Costilla County
• Prepared By: CWCB
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

Preface

1.0

TABLE 0,' CON1'J::NTS

PaCle

Introduction .................................
1.1 Purpose ................................
1.2 Authorization..........................
1.3 Acknowledgments........................
1.4 Related Flood Studies .... .... .... ......

2.0

Study
'.1
2.2
2.3
U
U
'.6
U
U

3.0

1
1
1
,
,

Area.................................. .
Location.............................. .
Human Settlement.......................
Study Reaches..........................
Rio Grande Basin.......................
1'rinchera Creek Basin..................
Culebra Creek Basin ....................
Costilla Creek BaBin...................
Summary of Drainage AreaB ..............

.
.
,
,
,
12
12
12
"

Hydrologic Analysis.......................... 17
3.1 t'lood Characteristics.................. 17
3.2 Hi5torical Review...................... 17
3.3 St.ream Gage Dat.a ....................... 20
3.4 Reservoirs............................. 23
3.5 Irrigation Oitch'!s ..................... 23
3.6 Peak Flows............................. 26

4.0 Hydraulic Analysis........................... 30
4.1 ailse Mappinq ........................... 30
4.2 Flood Depths........................... 30
4.3 Review in th€ fi€ld .................... 31
4.4 z'looded Areas.......................... 31

- Tables _

1.
,.
3.
..
,.
6.
,.
6.

PaGe

Stream Reache5 ..................................... B
Drainage Areas..................................... 16
Historic Peak Flows................................ 19
Stream Gages Analyzed in TM-I ..... ..... ..... ....... 21
Stream Gages Anillyzed by the SCS ... ..... ........... 22
Major Reservoirs................................... 24
SUmmary of Hydrology..........................,.... 29
Depths of Flooding................................. 33

- Figures _

1.
,
3 .
..
,.

Location of Costilla County in Colorado............
Location of Costilla County in Rio Grande Basin.....
Major Drainage Basins Within Costilla County.......
Map of Major Reservoirs ............................
Hydrologic Determinations
..........................

p"l(le

S
6
1S
2S
2S

5.0 Interpretation and Use of Report............. 34
5.1 Flood Discharges....................... 34
5.2 ,'looded Area Maps...................... 34
5.3 Structural Measures.................... 35
5.4 Measures that Reduce Vulnerability..... 35
S.S Measures that Minimize Impacts ......... 36

- Plates_

Number

6.0 Eibliography ................................. 38

Indf'x of Floode(\ Area Maps............................. I
Flood",d Ar"d Maps...................................... 2-22