Culvert Prioritization Model: Aiding Communities in the Selection of Priority Restoration Projects

Transcription

1 Culvert Prioritization Model: Aiding Communities in the Selection of Priority Restoration Projects SNHPC Meeting January 24,

2 Undersized Culverts! Culvert Sizes (~7,500 VT culverts) 6,000 5,000 69% Number of Culverts 4,000 3,000 2,000 21% 2 1, % 2% 3% < >125 Culvert Size (% of Bankfull Channel Width)

3 Former culvert (MMI, 2015) New culvert 3

4 Project Area 4

5 Project Goals 1. Create an easy to use Excel based tool for municipalities to prioritize culvert replacements and stream crossing restorations. 2. Create a data driven tool that is flexible for continued local input of key transportation safety and environmental factors to prioritize infrastructure upgrades before emergency repairs are needed. 3. Get ahead of the storm and work with three pilot municipalities in developing, field testing, and implementing the tool. 4. Provide the tool and share information on its use with all eleven municipalities in the Piscataquog River Watershed. 5

6 Model Uses Municipalities Planning for a more flood resilient local road network. Screening and planning tool that informs governing boards and confirms local knowledge and experience. Enhances capital improvement planning and budgeting to target high risk locations first. Provides framework for local asset management. Provides data for hazard mitigation plan updates. Helps secure funding for culvert replacements. 6 State Information for SADES management systems. Assist agencies in ranking and scoring grant proposals. Identify sources of funding for culvert replacement. Potential template for the state to evaluate culverts and prioritize replacement of high risk culverts.

7 Existing Data 1. Geomorphic Compatibility (GC) How well a culvert matches the stream channel. 2. Structural (STR) Structural condition and approximate hydraulic capacity. 3. Aquatic Organism Passage (AOP) Existing connectivity and habitat reconnection potential; and 4. Criticality (C) How important the culvert is to the transportation network. 5. Risk (R) Combination of vulnerability and criticality. 7 Data Level 1 State and regional GIS data Data Level 2 Watershed and regional assessment data and GIS analysis Data Level 3 Local data

8 Final Screen Culvert Scoring System (V.7) Variable Data Level 1 (Watershed and Regional Data) Data Level 2 (Additional Regional Data) Data Level 3 (Local Data) Risk GC % Bankfull Width NH Geomorphic Compatibility Screen (NHGS) STR AOP Structural Condition (TU/SNHPC/NHGS) NH Aquatic Organism Passage Screen (TU/SNHPC) + Approximate Hydraulic Capacity (TU/SNHPC) None Local Data Indicating Poor Condition, Known to Cause Flooding, or Frequently Damaged + Habitat Gain + Fisheries Prioritization (NHFG) Risk GC Geomorphic Compatibility Aquatic Organism Passage AOP STR Structure Condition Criticality C Risk C NHDOT Highway Tiers + Proximity to Public Safety + Average Annual Daily Traffic (AADT) (NHDOT) Local Data on Critical Links, Floodprone Structures, etc. Risk Risk (R) = f(gc, STR, C) Data Level Score = Sum of Variable Data Levels Used in the Risk Screen 6 to 8 = High ; 5 = Moderate; 2 to 4 = Low 8 Lowest Risk Moderate Risk Highest Risk Prepared September 2016

9 9 Example of Final Screen Map

10 Example of Final Screen Map 10

11 Example of Final Screen Map 11

12 12 Pilot Screen Results Summary

13 13 Pilot Screen Results Summary

14 14 Example Town Results Summary

15 15 Example Town Results Summary

16 16 Example Town Results Summary

17 User Guide 17

18 Concept Design 18

19 Concept Design 19

20 Possible Funding Sources for Implementation NH Department of Transportation Federal and State Highway Funds NH Homeland Security and Emergency Management FEMA Hazard Mitigation Grant NH Department of Environmental Services, Wetlands Bureau Aquatic Resource Mitigation (ARM) Fund NH Fish & Game AOP Restoration US FWS AOP Restoration Local Conservation Funding Local Capital Improvement Programming Local Bonding 20

21 Thank You. By David Brooks By Chris Cornog 21

22 Supporting Slides 22

23 Existing Town Information 23

24 New Town Information 24

25 New Town Information Culvert # Location Overall Risk Comments RB_DIBK_02 Back Mt. Rd Moderate RB_DIBK_04 Back Mt. Rd High replaced with 4ft plastic in 2012 RB_DIBK_05 Bennington Road Moderate State owned RB_DIBK_06 Bennington Road High State owned RB_DIBK_07 School House Road Moderate 6ft cmp sleeved with5ft cmp, culvert of greatest concern RB_DIBK_08 2nd NH Turnpike N Low 3' concrete RB_DIBK_10 2nd NH Turnpike N Moderate stone RB_DIBK_11 2nd NH Turnpike N High??? Risk, this area not a flood hazard RB_DIBK_12 Mt. Road Moderate 3ft concrete RB_DIBK_13 Bennington Road High State owned RB_COBK_05 Old County Rd N Moderate double arch, condition critical, currently in bridge progam RB_SBPR_09 Udall Road High concur, severe flood hazard area RB_SBPR_09A Udall Road High concur, severe flood hazard area RB_SBPR_11 Reid Road Low check structure condition, severe corrosion RB_SBPR_16 Juniper Hill Road Low Replaced with Bridge RB_SBPR_17 Birdsall Road High Concur RB_SBPR_17 25 Birdsall Road Moderate cannot verify location

26 Geomorphic Compatibility (GC) Level 1 Data = Culvert Width as % of Bankfull Width % of BFW Score Less Than 75% Greater Than 75% and Less Than 85% Greater Than 85% 26

27 Structural Condition (STR) 27 Level 2 = Structure condition (STR) combined with approximate hydraulic capacity (AHC) NEW CONDITION OLD, RUSTED, COLLAPSING, or ERODING Approximate Hydraulic Capacity Approximate Hydraulic Capacity Flood Pass Transition Fail Flood Pass Transition Fail (RI year) Hw/D< >1.15 (RI year) Hw/D< > L H H 2 L H H 10 L H H 10 L H H 25 L M H 25 L H H 50 L M M 50 L H H 100 L M M 100 L M H Level 3 Data = Local Information Possible Local Variables Known poor condition Known cause of flooding Frequently Damaged NHDOT Redlist Bridge (for culvert with D > 10 feet) Score

28 Aquatic Organism Passage (AOP) LEVEL 1 = NH Aquatic Organism Passage Screen (AOP) VT Aquatic Organism Passage Coarse Screen Updated 2/25/2008 AOP Function Variables / Values Culvert outlet invert type Full AOP for all aquatic organisms Green (if all are true) at grade OR backwatered Outlet drop (ft) = 0 Reduced AOP for all aquatic organisms Gray (if any are true) cascade free fall AND No AOP for all aquatic for all aquatic organisms organisms except adult including adult salmonids salmonids Orange Red free fall AND > 0, < 1 ft OR 1 ft OR Downstream pool present = yes ( = yes AND = no OR ( = yes AND Downstream pool entrance depth / outlet drop n/m > 1 ) n/a < 1 ) OR Water depth in culvert at outlet (ft) < 0.3 ft Number of culverts at crossing 1 > 1 Structure opening partially obstructed = none none Sediment throughout structure yes no 28

29 Aquatic Organism Passage (AOP) LEVEL 2 SCREEN = Combined AOP Score with upstream habitat gained AOP Category LEVEL 3 SCREEN = Adjust score by habitat priority Upstream Habitat Gained Score AOP Category Minimum Habitat Gained Fishery Rank All N/A Fisheries Priority Locations (NHFG) Fishery Rank All N/A No BAT Result No BAT Result South Branch 1 Reduced No BAT Result Reduced <.25 mile North Branch 2 <.25 mile >=.25, <.5 Mainstem 3 >=.25, <.5 >=.5,<.75 mile Middle Branch 4 >=.5,<.75 mile >=.75 mile >=.75 mile No BAT Result No BAT Result No BAT Result Limited (strong swimmers only) <.25 mile <.25 mile >=.25, <.5 Limited (strong swimmers only) >=.25, <.5 >=.5,<.75 mile >=.5,<.75 mile >=.75 mile >=.75 mile No BAT Result No BAT Result No BAT Result <.25 mile <.25 mile None >=.25, <.75 None >=.25, <.75 >=.5,<.75 mile >=.5,<.75 mile >=.75 mile >=.75 mile Notes: Red indicates a high project priority structure (Poor AOP and good habitat recovery). 29

30 Criticality (C) Level 1 Data = NHDOT Highway Tiers NHDOT Highway Tiers Score Total Length (Miles) Percent 0 Private, Not maintained % Tier 1 Interstates, Turnpikes, and Divided Highways 1 0% Tier 2 Statewide Corridors 17 3% Tier 3 Regional Transportation Corridors 54 8% Tier 4 Local Connectors 8 1% Tier 5a Local Roads * 47 7% Tier 5b Local Roads (All Other) % Tier 6 Off Network 0 0% NOTES: Assume that Tier 4 and 5 to be adjusted locally where Towns see as more critical. *Minor Collector, Major Collector, or Minor Arterial Public Safety Proximity Within 0.5 mile of public safety (police, fire, hospital, schools) Between 0.5 and 1 mile of public safety NOTES: Derived in GIS. Score Level 2 Data = Average Annual Daily Traffic Level 3 Data = Local Information 30 Average Annual Daily Traffic (AADT) Score Possible Local Variables Score > 4000 trips Critical links (adjust Tier 4 and 5) 500 to 4000 trips Critical structure in floodprone area < 500 trips Near infrastructure High local traffic volume NOTES: Neighborhoods or Town centers Derived in GIS. Disruptive Detour Override (possibly downgrade) Highway Tier NOTES: Variables to be based on Town priorities. Data to be provided by Towns, and mapped in GIS.

31 Risk (R) 31 Vulnerability Criticality Risk GC STR C R Risk Level Notes 1 Highest risk level ^ 10 ^Predetermined score ^ 11 ^Predetermined score * 12 *Assumed (conservative) * 13 *Assumed (conservative) ^ 24 ^Predetermined score ^ 25 *Assumed (conservative) ^ 26 *Assumed (conservative) * 27 *Assumed (conservative) ^ 30 ^Predetermined score Lowest risk level

32 Data Level Variable Data Levels (GC, STR, C, AOP): Data Level Score 0 No Data Variable Data Data Level 1 Watershed/Regional Scale Data Level Sum Score 2 Additional Regional Data 2 to 4 Low 3 Local Data Provided by Towns 5 Moderate 6 to 8 High NOTES: For each structure, variable data levels are summed (GC+STR+C+AOP) and assigned a score. Data level scores are presented on screen maps in parentheses after ID. 32

33 Existing Information 33

34 Existing Information 34 (SNHPC, TU, DES, 2015)

35 Existing Information 35 (SNHPC, TU, DES, 2015)

36 Existing Hydraulic Capacity Information Hw/D> >Hw/D>0.85 Hw/D<0.85 (TU and SNHPC, 2014) 36

37 Recent Design Guidance 37 (Schiff et al., 2014)

38 Culvert Vulnerability Screening 38 (MMI, 2016)

39 Screening Culverts for Risk Reduction and AOP (MMI, 2014) VT116 39

40 Geomorphic Compatibility Screen 40 (Schiff et al., 2008)

41 Geomorphic Compatibility Screen 41 (Schiff et al., 2008)

42 Incorporating Culvert Restoration into Paving 42 (MMI, 2013)