N.D. Admin Code 69-05.2-08-14 - Permit applications - Permit area - Alluvial valley floor resources

1. If land within the permit or adjacent area is identified as an alluvial valley floor and mining may affect it or waters that supply alluvial valley floors, the applicant shall submit a complete description of the alluvial valley floor resources and characteristics that allow the commission to determine:

a. The characteristics necessary to preserve essential hydrologic functions during and after mining.

b. The significance of the area to agricultural activities.

c. Whether the operation will cause, or presents an unacceptable risk of causing, material damage to the quantity or quality of surface or ground waters that supply the alluvial valley floor.

d. The effectiveness of proposed reclamation under North Dakota Century Code chapter 38-14.1 and this article.

e. Specific environmental monitoring required to measure compliance with chapter 69-05.2-25 during and after mining and reclamation operations.

2. The alluvial valley floor baseline data required to make the determinations listed in subsection 1 must include:

a. Geologic data, including structure and surficial maps, and cross sections.

b. Soils and vegetation data, including a detailed soil survey and chemical and physical analyses, a vegetation map and narrative descriptions of quantitative and qualitative surveys, and land use data, including an evaluation of crop yields.

c. Surveys and data for areas designated as alluvial valley floors because of their flood irrigation characteristics must also include streamflow, runoff, sediment yield, and water quality analyses describing seasonal variations, field geomorphic surveys, and other geomorphic studies.

d. Surveys and data for areas designated as alluvial valley floors because of their subirrigation characteristics, must also include geohydrologic data including observation well establishment for water level measurements, ground water contour maps, testing to determine aquifer characteristics that affect waters supplying the alluvial valley floors, well and spring inventories, and water quality analyses describing seasonal variations, and of the same overburden parameters specified in section 69-05.2-08-05 to determine the effect of the operations on water quality and quantity.

e. Plans showing how the operation will avoid, during mining and reclamation, interruption, discontinuance, or preclusion of farming on the alluvial valley floors unless the premining land use has been undeveloped rangeland which is not significant to farming and will not materially damage the quantity or quality of water in surface and ground water systems that supply these alluvial valley floors.

f. Maps showing farms that could be affected by the mining and, if any farm encompasses all or part of an alluvial valley floor, statements of the type and quantity of agricultural activity on the alluvial valley floor and its relationship to the farm's total agricultural activity including an economic analysis.

3. The surveys should identify those geologic, hydrologic, and biologic characteristics of the alluvial valley floor necessary to support essential hydrologic functions. Characteristics which must be evaluated in a complete application include:

a. Characteristics supporting the function of collecting water which include:

(1) The amount and rate of runoff and a water balance analysis, with respect to rainfall, evapotranspiration, infiltration, and ground water recharge.

(2) The relief, slope, and density of the network of drainage channels.

(3) The infiltration, permeability, porosity, and transmissivity of unconsolidated deposits of the valley floor that either constitute the aquifer associated with the stream or lie between the aquifer and the stream.

(4) Other factors that affect the interchange of water between surface streams and ground water systems, including the depth to ground water, the direction of ground water flow, the extent to which the stream and associated alluvial ground water aquifers provide recharge to, or are recharged by bedrock aquifers.

b. Characteristics supporting the function of storing water which include:

(1) Surface roughness, slope, and vegetation of the channel, floodplain, and low terraces that retard flow.

(2) Porosity, permeability, water-holding capacity, saturated thickness, and volume of aquifers associated with streams, including alluvial aquifers, perched aquifers, and other water-bearing zones found beneath valley floors.

(3) Moisture held in soils within the alluvial valley floor, and the physical and chemical properties of the subsoil that provide for sustained vegetation growth or cover during extended periods of low precipitation.

c. Characteristics supporting the function of regulating the flow of water which include:

(1) The geometry and physical character of the valley, expressed in terms of the longitudinal profile and slope of the valley and the channel, the sinuosity of the channel, the cross section, slopes, and proportions of the channels, floodplains, and low terraces, the nature and stability of the streambanks, and the vegetation established in the channels and along the streambanks and floodplains.

(2) The nature of surface flows as shown by the frequency and duration of flows of representative magnitude including low flows and floods.

(3) The nature of interchange of water between streams, their associated alluvial aquifers and any bedrock aquifers as shown by the rate and amount supplied by the stream to associated alluvial and bedrock aquifers (i.e., recharge) and by the rates and amounts supplied by aquifers to the stream (i.e., baseflow).

d. Characteristics which make water available and which include the presence of land forms including floodplains and terraces suitable for agricultural activities.

Notes

N.D. Admin Code 69-05.2-08-14

Effective August 1, 1980; amended effective May 1, 1990.

General Authority: NDCC 38-14.1-03

Law Implemented: NDCC 38-14.1-21