VSP Work Plan Agricultural Activities and Critical Area Functions Report to Watershed Group January 20, 2015 1
Overview • Purpose Statements • Critical Area Functions • Agricultural Activities in Current Regulations • Agricultural Impacts on Critical Areas • Potential BMPs for Ag Activities • Questions 2
Purpose Statements • Aqui uifer er Rec echarge arge Are reas as – To maintain groundwater recharge; – To prevent the degradation of groundwater resources; – To recognize the delicate balance between surface and groundwater resources; – To balance competing needs for water while preserving essential natural functions and processes As per Title 17.15 Agricultural Activities CAO 3
Purpose Statements • Flo loodplai odplains, ns, St Stre reams, ams, an and Wetl etlan ands ds – To preserve natural flood control, stormwater storage and drainage or stream flow patterns; – To control siltation, protect nutrient reserves and maintain stream flows and stream quality for fish and marine shellfish; – To prevent turbidity and pollution of wetlands, streams and fish or shellfish bearing waters and to maintain the associated wildlife habitat; and – To minimize the loss of wetlands and to increase the quality and function of wetlands within Thurston County. As per Title 17.15 4
Purpose Statements • Impo portan ant t Hab abit itat ats s an and d Spe pecie ies – To preserve habitat adequate to support viable populations of native wildlife in Thurston County; – To preserve high quality native habitat areas; – To provide habitat protection which will retain a viable population of these important animal species; and – To encourage nonregulatory methods of habitat retention whenever practical, through eduction. Open Space Tax Program, and such private programs as conservation easements deeded to land trusts, and additions to the Thurston County park system. As per Title 17.15 5
Purpose Statements • Geo eologic logic Hazar ard d Area eas – To minimize damage to personal health and property due to landslide, seismic, volcanic, or other naturally occurring events; – To control erosion, siltation, and stream quality to protect fish and marine shellfish; – To reduce the potential shoreline erosion along the bluffs of Puget Sound; – To protect areas with high potential for marine aquaculture activities from degradation by upland land uses; and – To minimize the risks associated with old or abandoned coal mines. As per Title 17.15 6
Critical Area Functions • Critical tical Aqui uifer er Rechar echarge ge Ar Areas eas – Groundwater replenishment: water filters into the ground and recharges underground aquifers – Vegetated/forest soils function as filter for water before it reaches the aquifer – Provides water for irrigation and drinking water 7
Critical Area Functions • Wetl etlan ands ds – Biodiversity protection: food web and habitat functions – Hydrologic functions: flood storage and retention reducing flooding and maintaining water regimes, groundwater discharge/recharge, maintaining and protecting water quality – Sediment retention and erosion control – Retention of nutrients and other substances 8
Critical Area Functions 9
Critical Area Functions • Flooding looding – Floodplain connectivity is critical to a properly functioning stream-riparian ecosystem – Floodwaters carry sediment, organic material, nutrients, and biota to and from the floodplain – Migration of species: allows for foraging and reproduction outside of the river channel – Flushes and maintains healthy habitats in river pools and can reduce algal blooms 10
Critical Area Functions • Wi Wildl ldlif ife e Hab abita tat t an and Speci ecies es – Ecological functions of organisms support the trophic structure of ecosystems • More biodiverse systems have wider arrays of ecological functions – Functions and benefits of healthy habitats include the creation of healthy soil, clean and abundant water, fertile crops, and protection from flooding and climate extremes 11
Critical Area Functions • Geo eologic logic Haz azar ard d Ar Areas eas – Erosion: sediment deposition from material being carried downslope maintains the functions of riverine, riparian and marine habitats – Landslides: Deposits of LWD (important to the natural function and health of aquatic areas) provides nutrients, shelter from predators to fish and amphibians, some shade, and serves to stabilize stream channels and beach environments 12
Agricultural Activities • Current Regulations • Agricultural land uses and activities in Table 2 at the end of Title 17.15 are allowed in Aquifer Recharge Areas • Agricultural land uses and activities listed in Table 5 at the end of Title 17.15 are allowed in Geologic Hazard Areas, Flood Hazard Areas, Important Habitat Areas, and Wetlands 13
Impacts of Agricultural Activities on Critical Area Functions Important Geologic Aquifer Ag Activity Wetlands Habitats and Hazardous Floodplains recharge Species areas Building road Changes in Decreases water Surface water Damage to access & Loss of habitat water infiltration and changes-temp buildings, impervious and connectivity infiltration, fine recharge and chemicals erosion surfaces sediment Altering Changes in Changes in Loss and Can increase hydrology: groundwater surface water degradation of Erosion flows at certain ditches/ponds flow/quantity flow/quantity habitat times Changes to Decrease in Reduction of groundwater stream Changes to water available, Irrigation flow/table, flow/quantity Erosion stormflow accumulation of transport available for volume/peak salts in soil nutrients, etc. wildlife Loss of filtration, Loss of Removal of Loss of filtration Erosion, slope Channel erosion, temp control habitat/LWD, vegetation function stability sedimentation from shading reduced shading Flood control: Channel and Changes in Loss of habitat Changes to dikes, flood Loss of wetlands bank erosion, groundwater structure and storm flow, plain fill and in floodplains reduced bank flow complexity channel erosion 14 armoring banks stability
Potential Best Management Practices to address the impacts of Ag Activities on Critical Areas Important Aquifer Wetlands and Geologic Ag Activity Habitat and Floodplains Recharge Areas streams Hazardous Areas Species Vegetated filter Vegetated filter Native vegetation Slows runoff, strips remove strips remove Vegetated Filter increases retention provides wildlife sediment, sediment, Strips habitat, cover, and of flood waters, chemicals, and chemicals, and refuge and traps sediment nutrients nutrients Increase soil Uptake nutrients Can reduce Filter sediment porosity, reduce (reduce nitrogen establishment of from shallow flood Cover Crops compaction, and leaching), filter waters, and reduce non-native invasive aid infiltration, sediment species run off volume uptake nutrients Promotes bio- based and Protects at-risk Integrated Pest ecologically benign Reduces source of habitat and non- Management alternatives: non-point pollution target species protects clean water Reduces source of Conservation tillage Reduces source of Nutrient pollution and and other practices pollution and water Management groundwater reduce erosion and quality degradation contamination nutrient loss Increase filtration Uptake nutrients, Slows runoff, Vegetation provides Provides wildlife Native vegetation of chemicals and filter sediment, soil stability and increases retention habitat, cover, and 15 buffer zones nutrients from microclimate of flood waters, can reduce refuge groundwater control landslide hazards and traps sediment
Questions? • Contact Charissa Waters, Thurston County Resource Stewardship Department – watersc@co.thurston.wa.us – (360) 786-5541 16
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