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South Dakota: Budget the exposed components rather than one future rate
Start with EIA: supply, demand, weather and storage price drivers. The table below links this decision to the represented gas companies in South Dakota. It does not establish service or supplier availability for every account.
Create a scenario register
Keep monthly usage, index assumptions, location differential, fixed charges and exposed adjustments in separate columns. Name the source and observation date for market data. A supplier’s written formula determines how an observation reaches the bill.
Use a revision trigger
Set an internal review date and identify operational changes that justify a new budget: closure, added shifts, equipment replacement or a corrected baseline. Keep a downside scenario visible without presenting it as a prediction or creating unsupported urgency.
South Dakota utility application
| Gas service company | Component requiring a separate forecast | Primary reference |
|---|---|---|
| NorthWestern Energy | Sales gas-cost component versus transport, balancing and supplier costs | Official program / tariff |
| Montana-Dakota Utilities | Purchased-gas adjustment under sales versus transportation and retained gas obligations | Official program / tariff |
| MidAmerican Energy | Sales gas-cost component versus transport, balancing and supplier costs | Official program / tariff |
| Watertown Municipal Utilities | Local gas rate and any gas-cost adjustment | Official program / tariff |
NorthWestern Energy: the program detail behind this decision
The South Dakota PUC lists distinct commercial sales and transportation schedules by gas company. NorthWestern lists Rate 87 transportation; MidAmerican lists monthly-metered transportation and transportation of customer-owned gas. These require their own qualification and agreements, rather than statewide small-business open enrollment. Sd Current Tariffs.
Apply the evidence to an account file
Give Sales gas-cost component versus transport, balancing and supplier costs its own documented model assumptions. Validate Actual gas utility, commercial class and applicable transport schedule before using a utility comparison component; a forecast for a different class is not this meter’s available alternative.
An assumption register that can be updated without rewriting history
Record each month’s therms, price mechanism, assumed benchmark, location/service adders, recurring fees and retained utility charges. Keep the original budget alongside revisions and actuals. Change one driver at a time to identify sensitivity, then test a combined adverse scenario. For a fixed commodity offer, leave that defined component fixed over its contractual months while varying usage and genuinely exposed items. Do not apply a current spot observation to every future month or label an invented scenario as the forecast available to the customer.
Turn the review into a calculation
Build a monthly weighted budget. Enter documented assumptions in matching energy units. Keep any charge outside both supply offers separate; the result does not establish eligibility or an available quote.
Read the South Dakota utility guide for the wider service-company distinctions. Convert billed gas units using the bill’s heat-content factor when moving from volume to energy.
Sources and review notes
- EIA: supply, demand, weather and storage price drivers
- South Dakota PUC natural gas tariffs
- Mdu Tariffs
- Sd Utility Directory
Reviewed October 16, 2026. Program information can change. Confirm the effective utility tariff, supplier availability and written offer before proceeding. Examples and planning tools are educational; they are not executable quotes or verified customer results.