Henry Van Offelen Natural Resource Scientist MN Center for Environmental Advocacy

Size: px

Start display at page:

Download "Henry Van Offelen Natural Resource Scientist MN Center for Environmental Advocacy hvanoffelen@mncenter.org"

Rosemary Franklin
8 years ago
Views:

1 Henry Van Offelen Natural Resource Scientist MN Center for Environmental Advocacy

2 Wetland study slide

7 Water Quality

9 NRE goals in watershed plans Protect habitat that remains. Enhance habitats where opportunities exist. More wetlands. (target to priority areas) More grasslands. (target to priority areas) More filter/buffer strips. More BMP implementation. Create better hydrologic conditions (attenuate high flows, better low flow conditions). Channel rehabilitation and restoration and connectivity where appropriate.

10 Project 60- Red Lake Watershed District Channel Rehabilitation Impoundments Land use change

11 TP 11 FDR measures and associated NRE opportunities 1) Reduce Flood Volume a) Restore or create wetlands (providing infiltration and evapotranspiration) b) Use cropland BMPs (increase infiltration and evapotranspiration) c) Convert cropland to prairie or other types of perennial grassland (e.g., Conservation Reserve Program (CRP) and Reinvest in Minnesota (RIM) to increase infiltration and evapotranspiration) d) Convert land use to forest (forested areas generally have the lowest runoff coefficients, due to high interception and evapotranspiration) e) Other beneficial uses of stored runoff. Associated NREs Protect, restore, enhance existing habitats. Improved hydrologic conditions for streams.

12 TP 11 FDR measures and associated NRE opportunities 2) Increase Conveyance Capacity a) Channelization (increasing the flow capacity of existing channels or flowages) b) Drainage (creating new or improved conveyance capacity) c) Diversions (of flood waters around a current damage area) d) Setting back existing levees (to restore floodway capacity) e) Increasing road crossing capacity Associated NREs Potential stream corridor restoration associated with setting back levees Potential water quality benefits for more stable drainage ditches and installation of side inlets

13 TP 11 FDR measures and associated NRE opportunities 4) Protection/Avoidance a) Urban levees b) Farmstead levees c) Agricultural levees d) Evacuation of the floodplain (removing people and flood-prone facilities and converting to more flood-compatible land uses) e) Floodproofing f) Flood warning and emergency response planning Associated NREs Potential stream corridor restoration associated with floodplain evacuation.

14 TP 11 FDR measures and associated NRE opportunities 3) Increase Temporary Flood Storage a) Impoundments (with or without a normal pool, to detain water in excess of downstream channel capacity) b) Restored or created wetlands (functioning as impoundments) c) Drainage (to lower surface water and groundwater levels, which increases infiltration and temporary storage in the upper soil horizons) d) Culvert sizing (to increase temporary storage by widespread metering of runoff close to its source) e) Setting back existing levees (to restore floodplain storage areas) f) Overtopping levees (to utilize diked floodplain storage capacity when critically needed)

15 FDR measure Impoundments Wetlands Drainage (of existing areas) Culvert Sizing Setting back existing levees Potential NRE Opportunity Land use change in impoundment footprint resulting in: Wetland and wetland like habitat creation, Grassland habitat creation, Improved downstream hydrology. Wetland and grassland restoration Better water management of wetland habitat Improved downstream hydrology, filter strips along ditches Channel rehabilitation Potential NR loss Stream channel and corridor loss, Lost connectivity, Wetland and grassland fill/inundation and loss. Water management inconsistent with NR goals??? Overtopping levees Channel rehabilitation, wetland and grassland restoration?

16 NRE options for typical FDR impoundment projects Do nothing. Invest in habitat elsewhere in the area/watershed. Creative use of borrow areas. Operate to augment low flows. Plant perennial vegetation in project footprint. Expand project footprint. Channel rehabilitation in the area/watershed. Widespread implementation of land and drainage BMP in the area/watershed.

17 Technical Paper 14 PURPOSE: To develop a method that would be used by watershed project teams and the FDRWG to help determine a projects consistency with the NR related goals in the Mediation Agreement and to help establish project funding priorities for NR components of FDR projects.

18 We have work to do. Wildlife Habitat Water Quality Flood Damage Reduction

22 20% Flow Reduction Goal

23 20% footprint if storage as primary approach Assume equivalent of 800,000 ac ft in Minnesota Assume 5, 8, and 10 foot average depth Average Depth Footprint (acres) 5 160, , ,000 Percentage of Land for Footprint Timing Zone Area (acres) 80k ac 100k ac 160k ac Early 2,396,707 Middle 4,737, % 2.1% 3.4% Late 4,174,943

24 Where we are headed next?

25 Building Decision Support Information and Applications for the Red River Basin: Achieving targeted implementation of Flood Damage Reduction, Sediment Reduction, and Fish and Wildlife Habitat Projects Project Team: Henry Van Offelen, MN Center for Environmental Advocacy, Grit May and Charles Fritz, International Water Institute Mark Deutschman and Brian Fischer, Houston Engineering

29 Permit Complexity Map

31 Annual Stream Runoff and Climate in Minnesota s River Basins Vandegrift and Stefan, U of M The largest increase in runoff coefficients was found in the Red River of the North and the Minnesota River Basins, the two basins with the lowest runoff, located in the former prairie regions. Runoff coefficients in some tributary or subwatersheds have doubled; there is more runoff and more total stream flow for the same amount of precipitation in these basins in more recent times. The smallest change in runoff coefficients was found in the Lake Superior and Rainy River Basins, and in the St. Croix River and Chippewa River (Wisconsin) watersheds, all in the eastern part of the region studied.

Red River Basin Flood Damage Reduction Framework

Red River Basin Flood Damage Reduction Framework Red River Basin Flood Damage Reduction Work Group Technical and Scientific Advisory Committee Technical Paper No. 11 Principal Authors: Charles Anderson,