Chesapeake Assessment Scenario Tool

The Chesapeake Assessment Scenario Tool (CAST) is a web-based water quality and stormwater management planning and modeling tool. It is capable of assessing total maximim daily loads (TMDLs), nonpoint source pollutant management, and municipal stormwater programs across the Chesapeake Bay basin. It allows users to assess the efficacy and cost of various best management practices (BMPs) for meeting nitrogen, phosphorus, or sediment load goals.

Chesapeake Bay Program
Model Information
For more information about this model, go to
Spatial Resolution
The spatial resolution has an average segment size 66 square miles with a variable grid size.
Temporal Resolution
Time step are 15-minute. Output is recorded as seasonal or annual averages.
CAST stores the geographic area, cost and implementation level associated with each best management practice as well as the load for each sector and land use
Intended User
practitioner, decision maker
Model Type
Inclusion of Climate Change
Climate conditions are incorporated though the scenarios developed in the scenario builder.
Geographic Region
Chesapeake Bay
Data Requirements
data provided by the user
Source Code Availability
closed source
Computational Burden
Scenario Modeling
batch mode described
Coding Language
Operating System
not applicable
Mathematical Approach
numerical, simulation, spatial
Maintenance Plan
Date of Last Known Update
not available
User Manual
go to documentation at not available