DO in river: This stock represents the amount of DO (dissolved oxygen) that we are measuring over a period of time. The unit of this stock is mg/L.

Oxygen by Photosynthesis: This flow represents the amount of oxygen being added to the river by photosynthesis.

Photosynthesis factor: This flow represents the amount of oxygen being added to the river by photosynthesis.

Wind: This converter changes the speed of the wind on the water.

Oxygen by Aeration: This flow represents the amount of oxygen being added to the river by the wind and turbulence

Turbulence: This converter is directly proportional the wind speed.

Turbulence Factor: This converter uses a lookup table to determine the amount of DO develop by quantity of the turbulence.

Oxygen used by sediment or sewage: This stock represents of DO absorbed by the sediment or sewage in the river.

Sewage load: This converter sets the level of DO absorbed by the sediment or sewage in the river.

Respirations by Organisms: This stock represents, in one large block, all of the oxygen-breathing organisms in the river.

Oxygen to Atmosphere: This stock represents the oxygen, which is automatically released to the atmosphere when the water reaches a specific level of DO,