General Permit for Activities Promoting Waterway - Floodplain Connectivity [working title]

Transcription

1 General Permit for Activities Promoting Waterway - Floodplain Connectivity [working title] Purpose These rules set forth the conditions under which a person may, without an individual removal-fill permit from the Department, place or remove material in waters of this state for the purpose of promoting waterway-floodplain connectivity for beneficial outcomes including elevated water tables, regularly flooded stream-adjacent surfaces, sediment deposition and soils improvement, increased channel complexity, riparian vegetation recovery and slow-water aquatic habitat development. Definitions (1) Beaver dam analogue means a structure within a waterway constructed primarily from organic material, and which may be supplemented by stream bed and bank materials, serving to mimic the hydrological, geomorphological, and ecological functions of natural beaver dams or assist beavers with the construction of natural beaver dams. (2) Incised or eroded waterway means a waterway that has been scoured by erosion to the extent that the channel bed elevation has lowered relative to its historic floodplain and the waterway has reduced ecological functionality because it has lost connectivity with the historic floodplain, as characterized by water table or water surface elevation lowering, the loss of natural wetland, riparian and meadow conditions in the adjacent surfaces, reduction in over-bank flood frequency or sediment deposition, the loss of diversity of fish and other animal species or the presence of dry land species that have encroached from adjacent uplands. (3) Malheur Lake Drainage Basin means the area included within Hydrologic Unit Codes , , , , , , , and Comment [KDJ1]: HB 3217 definition with a few friendly amendments as noted. Deleted: the absence of Deleted: ing Comment [KDJ2]: This is the same watershed proposed in HB 3217, only defined by HUC codes which is DSL s standard watershed nomenclature. (4) Native migratory fish is defined in ORS (5) Restoration check dam means a low-profile structure within a waterway and may extend to the historic floodplain, constructed from organic and or non-manufactured inorganic material (e.g., dirt, rock, gravel) in a manner designed to raise the water table and water surface elevations to the level of the historic floodplain by slowing, but not preventing water flow to promote floodplain connectivity. 1

2 Eligibility Requirements (1) Purpose. The project must be for the purpose defined in. (2) Non-tidal waters. The project must be located in non-tidal waters only. (3) Wetlands. The project involves no permanent loss of wetlands located above the ordinary high water elevation of any waterway proposed for treatment. (4) For beaver dam analogues: (a) Project sites are limited to incised or eroded waterways with a gradient less than 4%, a bankfull width less than 25 feet and a valley width of greater than 100 feet. The Department may allow alternative gradients or widths upon demonstration of current or historic beaver activity in the project area. (b) Project sites are limited to waterways historically inhabited by beaver but beaver are not currently successfully constructing or maintaining dams, or where reinforcement of existing beaver dams is needed. (5) For restoration check dams: (a) Project sites are limited to incised or eroded waterways within the Malheur Lake Drainage Basin. (b) Project sites are limited to waterways with a gradient less than 4%, a bankfull width less than 10 feet and a valley width of greater than 100 feet. (c) Project sites are limited to waterways not currently known to be inhabited by dambuilding beaver, or where there is insufficient habitat to support dam-building beaver. Comment [KDJ3]: Smaller bankfull width specified here to ensure lower stream power and smaller material sizes. (d) Project sites are limited to waterways that: (A) Do not currently contain, and did not historically contain, native migratory fish; or, (B) Do not currently contain, but did historically contain, native migratory fish where habitat is now the limiting factor, as determined by the OR Department of Fish and Wildlife. 2

3 General Permit-Specific Application Requirements In addition to the application requirements described in OAR , the applicant must provide the following information in the application: (1) Eligibility criteria met. The application must include maps, data and other information necessary to demonstrate that the proposed project meets the eligibility requirements specified in. (2) Drawings. The application must include scaled plan view, cross-section and longitudinal drawings illustrating the proposed dimensions of the structures relative to ordinary high water elevation and historic floodplain elevations. Drawings must show expected extent and depths of inundation zone. Plan view drawings must identify proposed spacing between structures and any infrastructure or other property improvements within the proposed area of effect. (3) Wetlands. For any wetlands above the ordinary high water line anticipated to be effected by the activity, describe the nature and expected duration of the effect, the estimated wetland area and the basis for the estimate (e.g., extent of hydrophytic vegetation, National Wetlands Inventory mapping, hydric soils mapping). The Department may elevate an application to individual permit status if, in the Department s judgement, permanent loss or other adverse effect to wetlands above the ordinary high water line is likely to occur. (4) Vegetation management plan. Application must include riparian planting and/or vegetation management plan considering the expected reach of water, likelihood of volunteer native plant recruitment, potential for spread of invasive species and management of potentially conflicting land uses in adjacent area (e.g., ungulate grazing). (5) Sediment control plan. If placement of inorganic material is proposed to occur in flowing waters, the application must include a description of best management practices to be used to minimize suspension of sediment in the waterway. (6) Fish exclusion plan. If fish are expected to be present in the waterway during construction, the application must include a description of methods to be used to exclude fish from the work area during construction. (7) ODFW determinations. For proposed restoration check dams, the application must include documentation from ODFW stating the current and historic presence of native migratory fish and whether waterway habitat is the limiting factor for native migratory fish presence now. 3

4 Authorized Activities (1) Beaver Dam Analogues. Up to 20 structures per authorization and not more than two structures per waterway meander wavelength or 14 channel widths. The two structures limitation may be waived by the Department upon demonstration that waterway conditions warrant the additional placements without causing significant adverse effects to water resources. (2) Restoration Check Dams. Up to 20 structures per authorization and not more than two structures per waterway meander wavelength or 14 channel widths. The two structures limitation may be waived by the Department upon demonstration that waterway conditions warrant the additional placements without causing significant adverse effects to water resources. General Permit-Specific Conditions (1) General Conditions Apply. All requirements, procedures and conditions set forth in OAR (General Conditions) apply to this General Permit. (2) Placement of inorganic material is subject to the following conditions: (a) Material is limited to the minimum quantity necessary to prevent under-scour of structure and reduce pore flow sufficient to ensure adequate over-topping flow and side flow to facilitate fish passage particularly during low-flow periods. Comment [KDJ4]: The following condition is already a requirement, by rule, for all General Permits: Hazards to Recreation, Navigation or Fishing. The activity must be timed not to interfere with or create a hazard to recreational or commercial navigation or fishing.] (b) Material is limited to the minimum quantity necessary to achieve the purpose pursuant to. (3) Natural Materials. Material used must be similar to materials currently or historically found naturally in the project area, except as otherwise allowed in (8)(g). (4) No cabling, wire, mortar or other materials that serve to affix the structure to bed, banks or upland is allowed. (5) No water withdrawals for beneficial use is allowed. (6) Native woody vegetation removal must be avoided to the maximum extent practicable. Where necessary, knock-down of woody vegetation to allow re-sprouting is preferred to removal. Any removed woody vegetation and any ground alteration by heavy equipment must be restored in equivalent numbers and contours at construction completion. 4

5 (7) No operation of heavy equipment in water is allowed. (8) For beaver dam analogues: (a) Structures must be no more than one-foot thick at the top as measured parallel to stream flow. (b) Structures must provide for a water surface differential of no more than one-foot at low flows, or otherwise provide clear path for fish passage through or around the structure via side channels during low flows. (c) Weaves must be sufficiently loose to provide porosity sufficient maintain fish passage through the structure and maintain fish rearing capacity in the impoundment area upstream of the structure. (d) To the extent practicable, river-run gravels or cobbles must be used where rock is warranted. (e) To extent practicable, posts must driven to a depth at least 1.5 times below the expected scour depth of the waterway. (f) Post driving using hydraulic methods must be conducted during low flow conditions and otherwise minimize driving within the wetted channel. (g) Wooden posts must be untreated and may utilize species not naturally found in the waterway reach. (9) For restoration check dams: (a) Only erosion-resistant rock from local upland sources may be used. Rock size is limited to the maximum necessary to prevent mobilization during high flow periods. Rock must be placed, not dumped, from above the bank line. (b) Structures must be designed to allow over-topping at? flows. Comment [KDJ5]: For RAC discussion. (c) Structures must provide for a water surface differential of no more than one foot at low flows, or otherwise provide clear path for fish passage around the structure via side channels during low flows. (d) Structures must incorporate natural materials to encourage vegetation. 5

6 (e) Structures must ensure sufficient fine material in the backwater area to prevent sub out. Monitoring and Reporting (1) Post-Project Reporting. Upon completion of the project, the project must be reported to the Oregon Watershed Enhancement Board at by completing the Oregon Watershed Restoration Inventory (OWRI) form. The DSL authorization number must be included on the reporting form. (2) Annual Monitoring and Reporting. Potential elements [subject to further discussion with RAC]: Pre-construction photos Annual high flow and low flow photographs from fixed photo-monitoring points Description of channel response aggradation of stream bed? Incised channel widening? Evidence increased floodplain connection? Other geomorphic changes? Hydrologic response - Impoundment max size and depth; change in downstream flow quantity/duration? Temperature monitoring at downstream end? Vegetation response in riparian zone and floodplain as compared to preconstruction condition Other habitat improvements/wildlife use observed? Any unexpected adverse changes to waterway, floodplain? Comment [KDJ6]: Requirements must be manageable by a range of permittees yet be useful for permit effectiveness monitoring. Term (1) Term. Notwithstanding the provisions of OAR , this GP will be reviewed within 10 years of the effective date of this rule for compliance with the review standards set forth in ORS through and the Department must find that the GP will not result in long-term harm to water resources of this state. The Department shall rely upon annual reports submitted pursuant to OAR and its own investigations for this 10-year review. (2) Amend or Rescind. The Department will amend or rescind this GP upon a determination that the activities conducted under the GP have resulted in or would result in unacceptable individual or cumulative environmental effects or long-term harm to the water resources of this state. The Department may rescind and require corrective action for any authorization under this General Permit upon a finding of unacceptable harm to water resources of this state. 6