HERO E&C has added four free screening maps to its Free tools: the Texas Soil Screening Map, the Texas Land Cover Screening Map, the Texas Atlas 14 Rainfall Map and the Texas Curve Number Screening Map. Like the Texas Flood Screening Map, each one works for a Texas address, a pair of coordinates or an uploaded or drawn site boundary, and each result lists its sources and links to check them with the agency that publishes the data.
Texas Soil Screening Map
The soil map shows the NRCS hydrologic soil group (A, B, C, D and the dual groups) with a plain-English meaning, the drainage class, hydric soil rating, depth to water table and bedrock, and the soil survey area and version, read live from NRCS Soil Data Access. For a boundary it lists the acres of each soil group and map unit, ready to copy into a spreadsheet. It is screening information, not a soil investigation or a wetland delineation.
Texas Land Cover Screening Map
The land cover map shows the USGS Annual National Land Cover Database (Annual NLCD 2025) class and impervious surface percent at a point, and for a boundary the acres, share and pixel count of each class, the developed share and the area-weighted impervious percent. Land cover is what covers the ground in satellite imagery. It is not zoning, land use or a survey of existing conditions, and the land cover map itself does not assign curve numbers; the Curve Number Map below does.
Texas Atlas 14 Rainfall Map
The rainfall map shows NOAA Atlas 14 Volume 11 depth-duration-frequency values, 5 minutes to 10 days and 1- to 1,000-year storms, for the NOAA grid cell at a point, with a chart, a CSV download and a copy of the depths for an HEC-HMS frequency storm. A boundary shows the values at its center and the lowest and highest values inside it, with no areal reduction factor. In a check of 22 Texas points, all 3,300 values matched NOAA’s Precipitation Frequency Data Server (PFDS), and every result links to PFDS for the same point, including its annual maximum series and confidence limits.
Texas Curve Number Screening Map
The curve number map pairs each Annual NLCD 2025 land cover pixel with the NRCS hydrologic soil group at its center and gives the runoff curve number from NRCS TR-55 (Technical Release 55, 1986) for average runoff condition (AMC II). Developed land uses each pixel’s own impervious share, with the impervious part at 98 and the rest as open space in good condition. A point shows the curve number with the arithmetic behind it. A boundary shows a worksheet of acres and curve numbers for each land cover and soil group pair, with the area-weighted curve number, ready to copy into a spreadsheet. Zoomed in, the map shows the curve number of every pixel.
The assumptions are on the page and can be changed: the hydrologic condition, the TR-55 table for range and brush (Table 2-2c for humid regions, or Table 2-2d for arid and semiarid range such as much of West and South Texas), and how dual and unrated soil groups are treated. Every value is labelled a screening value, not a design value, and the map does not compute runoff, peak flow or detention. In a check of 15 Texas points, its curve numbers matched values computed independently from the same national data and the TR-55 tables.
How they fit together
A result in one map links to the same site in the others, so a soil group, a land cover class, a 100-year rainfall depth and a curve number for one location are a few clicks apart. The Curve Number Map combines the soil groups and land cover that the Soil and Land Cover maps show. Files you upload are read in your browser and are not uploaded, and HERO E&C does not store your searches or files. The maps are screening tools: local drainage criteria decide the values used for design, and the results are not for design, construction, bidding, or permitting.
HERO E&C is a San Antonio civil and water resources engineering firm founded in 2025 and led by Dr. Seoyoung Kim, Ph.D., P.E., CFM. For a drainage study, a hydrologic model or a permit application built on site-specific data, contact HERO E&C.
Open the Rainfall Map Open the Soil Map Open the Land Cover Map Open the Curve Number Map