Jijuktu kwejk gee-gee wok-tok The Narrow River

Transcription

1 Jijuktu kwejk gee-gee wok-tok The Narrow River

2 Cornwallis River: WATERSHED

3 River Process Domains storage erosion debris generation: wood, stones transfer log jams, channel divergence deposition and settling beavers bank overflow silt washed on floodplains wood to estuaries

4 storage erosion debris generation: wood, stones Organic matter Carbon River Process Domains: HEADWATERS juvenile brook trout Oxygen: pools and riffles

5 organics and wood from Headwaters transfer River Process Domains MIDREACH.. Brook trout deposition and settling bank overflow log jams, channel divergence STREAM WIDENS AUTOTROPHIC

6 log jams, channel divergence River Process Domains Lower Reaches Brown trout..atlantic salmon beavers turbidity organics converted to bacteria,fungi invertebrate collectors deep river, lake-like

7 silt washed on floodplains River Process Domains Tidal river.. striped bass, sturgeon, shad freshwater tidal floods and storage wood to estuaries fish habitat..striped bass

8 Cornwallis River

9 Much of river headwaters are in good shape.

10 River headwaters are in good shape... but lost wetland storage capacity on Valley floor

11 Valley Floor Mixed farms Apples Railroads Markets In World War II, coffee, tea and sugar were rationed.. Nova Scotian self-sufficiency

12 Millions of Barrels Higher intensity agriculture on Valley Floor Nova Scotian Apple Production Arable land..corn..replaces Mixed farms and Apples y = 1E+103x R² = Year of Production (data from thesis: Anika Roberts-Stahlbrand Dalhousie)

13 conversion of wooded land, orchard land to plowed land: Ditches reduce water storage sediment washed into river..river fills in, reduced flood storage capacity

14 KENTVILLE: where the river waters meet the tide 2003 Flood from heavy rains Kentville, NS. West Main Street. Over 77mm over rain fell in a few days in 2003.

15 KENTVILLE: Where sea level rise and storm surges predicted to affect same area as river flood Open File Report: Webster McGuigan MacDonald AGRG 2012 Coastal flood risk from sea level rise and storm surge of the Kentville (West) Area, Kings Co. fm/pdf/ofm_ _agrg_dp.pdf

16 How do rivers work when we don t let them? The town has also raised the levels of dikes near Klondyke Street in the east end of town, which was also flooded when the river overflowed Estimators, Environment Department officials and cleaners are still looking at five homes that were flooded with oily water when the Cornwallis River overflowed onto the street and filled basements two weeks ago In the hard-hit Annapolis Valley, the rain flooded farmers' fields, filled basements and resulted in the Annapolis and Cornwallis rivers swelling beyond their banks in some places /Kentville-Council-moves-swiftly-on-flooding-issue/1 The report looks at the system's performance during flooding in March and April that forced a few dozen people from their homes on West Main Street and a section of the east end of town along the Cornwallis River.... The water was about a metre higher than in past flood conditions, he said, and higher than he has seen in his years in the town. Very few provide coverage for flood damage which means those with a flooded basement or leaking doors and windows are on their own. a) Consulting Engineer s Report Re: Flooding Sandy Dewar, the Town s Consulting Engineer, from the firm Hiltz and Seamone, prepared a report (attached to original Minutes), which determined the sources of flood waters during the spring floods of He reviewed those climatic issues and topographic conditions that contributed to the excessive flooding in late March, and further made recommendations to mitigate future flooding conditions in town. Points made: This report has not been reviewed in detail by Council The need for a full discussion period was identified. Public input from citizens is requested and Council will consider this during their discussion. Council will work with the Consulting Engineer to establish a proactive approach towards future flooding.

17 Wooded banks protect streams and are wildlife corridors

18 How productive are wet fields..what else could they be?

19 HARDSCAPE LINKED TO STREAM DOWNCUTTING AND EXOTICS.. Kentville Ravine Watershed Hardening East Tributary Central Elderkin West Parking Roads Residential Land Use WATERSHED IMPERMEABLE SURFACE Sub Watershed Watershed area Percent Impermeable (hectares) East Tributary (New Minas side) Central Elderkin Brook West Tributary

20 solutions?

21 Solutions: increase storage capacity of river watershed, reduce erosion, slow runoff, increase infiltration Protect and restore and create natural wetlands (e.g. swamps) Incentivize perennial agriculture..highbush, fruit, pastures, mixed farms Identify the flood control value of woodlots on Valley floor Restrict grazers to water holes Plant riparian edges..alders red maple willow..along all streams Incentivize conversion of low productivity wet fields to woodlot swamps Use permeable paving in all municipal and government lands, insist on swales for all new parking lots, make playground and education swales for schools Introduce children to canoeing and fishing Kids Conservation Core activities..tree planting, fish habitat, monitoring rare plants and indicators, Adopt a stream..invertebrates

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23 Many thanks to: Jijuktu kwejk Watershed Alliance Friends of the Kentville Ravine NS Young Naturalists Club Blomidon Naturalists The Municipality of Kings County and Councillors The Town of Kentville Friends of Cornwallis River Kings County Wildlife Association Agriculture Canada NS Department Natural Resources and friends