1. VILLAGE OF PATCH, NM, FEASIBILITY STUDY Village of Patch Case Study Seattle Environmen tal Planning Class June, 2009 US Army Corps of Engineers Albuquerque District 1 HO #s 2 & 2a Ch 1 Module 2 Patch,

2. Study Authority Authority “ The Secretary of the Army is hereby authorized directed to cause surveys for flood control and allied purposes, including channel and major drainage improvements to be made under the direction of the Chief of Engineers, in drainage areas of the United States and its territorial possessions, which include the localities specifically named in this section” … Patch, NM 2

3. VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District The study is located in Patch, NM. The purpose of the feasibility study is to determine Federal interest and optimize a flood damage reduction/ecosystem restoration plan for the city of Patch. Structures and roadways have been impacted by flows from the surrounding mountains, significantly flooding the community twice in the last 15 years. Flooding originates from two sources- Spring Canyon and Placitas Arroyo. Initial investigations determined that there is a likely Federal interest in constructing flood control projects in the area, the most probable alternatives being a small dam at Spring Canyon. Repeated flooding limits fishery populations. Regional Setting 3

4. Drainage Area VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 4 Patch, New Mexico

5. Floodplains VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 5 P atch

6. Flood History: The Village of Patch experienced significant Flood events in 1988, 2002 and 2006. FEMA and Corps’ analyses determined Spring Canyon is a flood threat to the Village of Hatch. The entire Village of Patch lies within a 100-year Floodplain VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 6

7. Flood Potential: Spring Canyon channel capacity is 1,300 CFX (100- year flow is-1% chance event-estimated at 2,600 CFS) Estimated average annualized flood damages of $10.1 million from Spring Canyon VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 7

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9. Existing and Likely Future Without-Project Conditions Physical Setting 17.2 square mile watershed draining from the south flowing north into the Rio Grande An upstream detention structure controls 15.4 square miles of the basin Elevation in the drainage drops from 6,000 ft to 4,030 ft Flooding events in 1988, 1992 and 2006 left three feet of water in the street VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 9

10. Existing and Likely Future Without-Project Conditions Physical Setting (continued) Once flows enter the village there is no clear drainage pathway into the Rio Grande; floodwaters remain in place until evaporated. The Village storm drainage system is sized for a 5-year event. Sediment renders the system largely inoperable during larger events VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 10

11. Existing and Likely Future Without-Project Conditions Social and Economic Conditions 2004 population of 10,661 1284 single residential structures within the 1% event floodplain 187 commercial structures within the 1% event floodplain 127 public structures within the 1% event floodplain 10 apartment within the 1% event floodplain VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 11

12. Existing and Likely Future Without-Project Conditions Social and Economic Conditions (continued) Median income for a household: $21,200 Many seasonal inhabitants “Chile capitol of the world” 172 homes with flood insurance VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 12

13. More Information Non-damaging Channel Capacity 10,300 cubic feet per second (cfs) 100-year flow 20,600 cfs Flood Damages Estimated average annualized flood damages $10.1 Mil Federal Disaster Area in 2006 VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 13

14. More Information Biological Communities Southern cottonwood- willow riparian forest occurs in Spring Creek Watershed. Salt Cedar dominates Placitas Arroyo. The forest provides canopy cover needed for sensitive nesting birds. VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 14

15. More Information Other Environmental Issues 10 lower-income apartment complex occurs in close proximity to the channel confluence of Spring Creek & Placitas Arroyo. New Mexico's Air Quality reviews imply that the high ozone levels in the northwest and southern parts of the state are part of a regional problem. VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 15

16. VILLAGE OF PATCH, NM, FEASIBILITY STUDY CULTURAL RESOURCES –During a site visit, black-on-white pottery fragments, burnt plant remains and long bones were observed eroding out of the river banks some 10 feet below the current floodplain. –Another 2 feet below, a hard clay band was observed in the river bank profile in Placitas Arroyo. 16

17. Plans Studied in Detail No Action Plan Non-Structural (Flood Warning) Channel Improvements Flood Detention oUpper Basin Structure oLower Basin Structure VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 17

18. Project Alternatives No Action Plan Non-Structural (flood warning) Non-Structural (raising/flood walls) Non-Structural (buyouts/relocation) Channel Improvements Flood Detention oUpper Basin Structure oLower Basin Structure VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 18

19. Impact Comparison of Alternative Plans Resource AreaNo ActionNon Structural NED DamChannel Improvements Land Use FarmlandNo Change to the Existing Condition Some Change to the Existing Condition Minimal impact to agricultural land use due to location of structure. High; Project located along agricultural lands. TransportationExisting ConditionMinor ImpactTemporary during Construction High; numerous road crossings and reroutes. NoiseExisting Condition Temporary Air QualityExisting Condition Temporary Water QualityExisting ConditionImprovedTemporary Settling BasinExisting Condition Hydrologic changeHydrologic Change Vegetation/WildlifeExisting ConditionImprovedMinor ImpactHigh Cultural ResourcesExisting Condition Minor Impact Visual ResourcesExisting ConditionHighMinor ImpactHigh 19

20. Recommended Plan Locally Preferred Plan 100-yr (1% Event) Dam in Lower Basin Features of the Locally Preferred Plan include Earth fill Dam approximately 14,000 ft. in length Concrete spillway 200 ft. in length Height of approximately 20 ft. Outlet Conduit 300 Acre-Foot Sediment pool 151 Acre-Foot Water Storage pool VILLAGE OF PATCH, NM, FEASIBILITY STUDY US Army Corps of Engineers Albuquerque District 20

21. Patch 21